Study guide
15.4 Professional Negligence, Informed Consent & Negligence Per Se
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1 Introduction & FYLSE Examination Guide
1.1 FYLSE Exam Structure, Passing Standard & Administration 1.2 Study Method, Pacing & MBE-Style Technique
2 Contracts: Mutual Assent, Capacity & Contract Formation
2.1 The Offer & Objective Theory of Assent 2.2 Termination & Irrevocability of Offers 2.3 Acceptance & the Mailbox Rule 2.4 Mirror Image Rule & UCC 2-207 Battle of the Forms 2.5 Mistake in Contract Formation 2.6 Fraud, Duress, Undue Influence & Illegality 2.7 Capacity to Contract
3 Contracts: Consideration, Estoppel & Implied Obligations
3.1 Consideration & the Bargained-For Exchange 3.2 Past & Moral Consideration, Pre-Existing Duty & Modification 3.3 Promissory Estoppel & Detrimental Reliance 3.4 Implied-in-Fact Contracts & Quasi-Contract 3.5 Implied Covenant of Good Faith, Fair Dealing & Indefinite Terms
4 Contracts: Third-Party Beneficiaries, Assignment & Delegation
4.1 Third-Party Beneficiary Contracts 4.2 Assignment of Rights 4.3 Delegation of Duties
5 Contracts: Statute of Frauds, Parol Evidence & Interpretation
5.1 Statute of Frauds: Contracts Within the Statute 5.2 Satisfying the Statute: Writing, Signature & Exceptions 5.3 The Parol Evidence Rule 5.4 Contract Interpretation & Canons of Construction
6 Contracts: Performance, Conditions, UCC Warranties & Breach
6.1 Conditions: Express, Constructive & Excuse 6.2 Substantial Performance vs. Perfect Tender 6.3 Cure, Rejection, Revocation & Installment Contracts 6.4 UCC Article 2 Warranties & Risk of Loss 6.5 Anticipatory Repudiation & Insecurity
7 Contracts: Remedies, Discharge & Changed Circumstances
7.1 Expectation Damages & Their Limitations 7.2 Reliance, Restitution & Liquidated Damages 7.3 Specific Performance & Injunctive Relief 7.4 UCC Article 2 Buyer's and Seller's Remedies 7.5 Impossibility, Impracticability & Frustration of Purpose 7.6 Discharge by Agreement: Rescission, Novation & Accord and Satisfaction
8 Criminal Law: Principles of Criminal Liability & Mens Rea
8.1 Actus Reus, Voluntary Acts & Omissions 8.2 Criminal Causation & Intervening Causes 8.3 Common Law & Model Penal Code Mens Rea 8.4 Mistake of Fact, Mistake of Law & Concurrence
9 Criminal Law: Inchoate Offenses & Accomplice Liability
9.1 Criminal Attempt & Impossibility 9.2 Solicitation & the Merger Doctrine 9.3 Conspiracy & Merger Doctrine 9.4 Accomplice Liability: Actus Reus & Mens Rea 9.5 Scope of Accomplice Liability, Withdrawal & Parties to Crime
10 Criminal Law: Homicide & Crimes Against the Person
10.1 Common Law Murder & Malice Aforethought 10.2 Degrees of Murder, Premeditation & Deliberation 10.3 The Felony Murder Rule & Its Limitations 10.4 Voluntary & Involuntary Manslaughter 10.5 Non-Homicide Crimes Against the Person
11 Criminal Law: Property Crimes, Theft & Habitation
11.1 Common Law Larceny 11.2 Embezzlement & False Pretenses 11.3 Robbery & Extortion 11.4 Receiving Stolen Property 11.5 Burglary 11.6 Arson
12 Criminal Law: Defenses: Capacity, Justification & Excuse
12.1 Insanity: The Four Legal Tests 12.2 Intoxication, Diminished Capacity & Infancy 12.3 Self-Defense & Defense of Others 12.4 Defense of Property, Habitation & Law Enforcement Privileges 12.5 Duress & Necessity 12.6 Entrapment & Mistake as an Excuse
13 Torts: Intentional Torts to Persons & Property
13.1 Intent, Motive & Incapacity in Intentional Torts 13.2 Transferred Intent 13.3 Battery & Assault 13.4 False Imprisonment 13.5 Trespass to Land 13.6 Trespass to Chattels & Conversion
14 Torts: Privileges & Defenses to Intentional Torts
14.1 Consent: Express, Implied & Capacity 14.2 Exceeding & Vitiating Consent 14.3 Self-Defense & Defense of Others (Tort) 14.4 Defense of Property & Recapture of Chattels 14.5 Public & Private Necessity 14.6 The Shopkeeper's Privilege
15 Torts: Negligence — Duty of Care & Breach
15.1 Duty of Care & the Foreseeable Plaintiff 15.2 Affirmative Duties to Act & Special Relationships 15.3 Standard of Care: The Reasonable Person & Children 15.4 Professional Negligence, Informed Consent & Negligence Per Se 15.5 Land Possessor Liability & Premises Duties 15.6 Breach of Duty & Res Ipsa Loquitur
16 Torts: Causation, Defenses, Multiple Tortfeasors, Wrongful Death & Damages
16.1 Cause in Fact & Multiple Actors 16.2 Proximate Cause & Intervening Forces 16.3 Contributory, Comparative Negligence & Assumption of Risk 16.4 Joint and Several Liability, Contribution & Indemnity 16.5 Vicarious Liability & Non-Delegable Duties 16.6 Wrongful Death & Survival Actions 16.7 Statute of Limitations & Claim Accrual 16.8 Tort Damages: Compensatory, Nominal, Punitive & Mitigation
17 Torts: Strict Liability & Products Liability
17.1 Strict Liability for Animals 17.2 Abnormally Dangerous Activities & Scope of Risk 17.3 Strict Products Liability & Defect Categories 17.4 Products Liability Under Negligence, Warranty & Misrepresentation 17.5 Defenses to Products Liability
18 Torts: Emotional Distress, Defamation, Privacy & Economic Torts
18.1 Intentional Infliction of Emotional Distress 18.2 Negligent Infliction of Emotional Distress 18.3 Common Law Defamation: Elements, Libel & Slander 18.4 Constitutional Limits, Privileges & Defenses to Defamation 18.5 Invasion of Privacy 18.6 Nuisance & Economic Torts
15.4 Professional Negligence, Informed Consent & Negligence Per Se
Key Takeaways Explain This Topic AI
A professional is held to the knowledge and skill of an ordinary member of that profession in good standing, established by the profession's own custom rather than by a jury's view of reasonableness.
Specialists are held to a national standard of care, and expert testimony is normally required to establish both the standard and its breach.
Informed consent is a separate duty requiring disclosure of the risks material to the patient's decision, excused in emergencies, where risks are commonly known, or where disclosure would be harmful.
Negligence per se substitutes a statutory standard for the reasonable-person standard where the plaintiff is within the class the statute protects and the harm is of the type the statute was designed to prevent.
The majority treats an unexcused violation as conclusive on duty and breach, leaving causation and damages for the plaintiff to prove, but the violation is excused where compliance would be more dangerous or was impossible, or in cases of incapacity or emergency.
Last updated: September 2026
- Professional Negligence, Informed Consent & Negligence Per Se
- 1. Professional Standard of Care (Malpractice)
Professionals who offer specialized services to the public—including physicians, surgeons, attorneys, certified public accountants, architects, and structural engineers—are held to a heightened, specialized standard of care.
Standard of Care Defined
A professional is required to possess and exercise the knowledge, skill, and care ordinarily possessed and exercised by members of that profession in good standing in similar communities ( Restatement (Second) of Torts § 299A ). Ordinary Negligence vs. Professional Malpractice
├── Ordinary Negligence (RPP) ──▶ Custom is merely ADMISSIBLE evidence of reasonableness; jury decides.
└── Professional Malpractice ──▶ Custom DEFINES the legal standard of care as a matter of law; expert required.
The Role of Custom: The Definitive Legal Benchmark
In ordinary negligence cases, evidence of industry custom is merely evidentiary—the jury is free to find an entire industry's custom negligent ( The T.J. Hooper ). By contrast, in professional malpractice , custom sets the legal standard of care as a matter of law :
If a physician, surgeon, or attorney conforms to the accepted, customary practice of their professional peers in good standing, the professional cannot be held liable in negligence as a matter of law , even if the patient or client suffered a tragic adverse outcome.
Under the "respectable minority" or "two schools of thought" doctrine , a physician does not breach the standard of care by adopting a recognized method approved by a reputable minority of the profession, even if a majority of practitioners favor a different approach.
Conversely, an unexcused departure from established professional custom constitutes a breach of the standard of care.
The Requirement of Expert Testimony
Because lay jurors lack the technical training to assess surgical protocols, pharmacological interactions, or complex estate tax filings, the plaintiff in a professional malpractice action must introduce expert witness testimony to establish:
The applicable customary standard of professional care; and
The defendant's deviation from that standard.
The "Common Knowledge" Exception: Expert testimony is excused only where the professional's negligence is so glaringly obvious that a layperson's everyday common sense is sufficient to recognize breach (e.g., a surgeon amputating the healthy right leg instead of the diseased left leg, a dentist extracting the wrong tooth, or a surgical team leaving an eight-inch steel retractor inside an abdominal cavity).
Geographic Standards: The Evolution of Locality Rules
Strict Locality Rule (Historical Common Law): Measured the physician's conduct exclusively against other doctors practicing in the exact same town or rural locality . (Largely repudiated due to the "conspiracy of silence" among small-town physicians unwilling to testify against colleagues).
Similar Locality Rule (Transitional / Minority): Measures conduct against physicians practicing in the same or similar communities , taking into account geographic size, population density, and medical equipment availability.
National Standard (Modern Majority): For board-certified specialists (e.g., board-certified cardiologists, neurosurgeons, radiologists), the standard of care is measured against a uniform nationwide standard , reflecting standardized board examinations, national medical journals, and uniform residency accreditation.
2. The Doctrine of Informed Consent
A distinct species of professional medical negligence is the failure to secure the patient's informed consent prior to a medical or surgical procedure ( Canterbury v. Spence , D.C. Cir. 1972).
The Physician's Duty of Disclosure
Prior to performing a medical intervention, a physician owes an affirmative duty to disclose to the patient:
- The nature and character of the proposed procedure;
- The potential material risks, hazards, and complications ;
- The medically recognized alternatives (including the alternative of non-treatment); and
The anticipated probability of success.
Two Competing Disclosure Standards
Jurisdiction / Approach Standard of Disclosure Definition & Legal Test
Physician-Oriented Standard (Traditional / Minority) Professional Custom Physician must disclose what a reasonable, customary physician in the same community would disclose under similar circumstances. Requires expert testimony.
Patient-Oriented Standard (Modern Majority / California) Materiality of the Risk Physician must disclose all risks that a reasonable person in the patient's position would deem material to making an informed decision. No expert testimony needed on materiality.
Causation in Informed Consent Actions
To prevail on an informed consent claim, the plaintiff must prove objective causation :
It is not enough that the undisclosed risk materialized and injured the patient.
The plaintiff must prove that a reasonable prudent person in the patient's position would have declined the treatment had the material risk been disclosed.
The patient's self-serving, hindsight testimony ("I never would have agreed to surgery if I knew there was a 2% risk of nerve damage") is insufficient if a reasonable person facing the medical crisis would have proceeded with the surgery regardless.
Recognized Exceptions to Informed Consent
Emergency: The patient is unconscious or incapacitated, immediate treatment is necessary to preserve life or limb, and no authorized surrogate is available.
Therapeutic Privilege: Extremely narrow common-law privilege where disclosure of the risk would so severely destabilize a psychologically fragile patient as to make rational medical decision-making impossible.
Commonly Known / Inherent Risks: Risks that are universally understood by laypersons (e.g., that an open surgical incision entails mild pain and risk of superficial infection).
3. Statutory Standards of Care: Negligence Per Se
Under the doctrine of negligence per se , a civil court adopts the requirements of a penal safety statute, penal ordinance, or administrative safety regulation to establish the civil standard of care, replacing the general Reasonable Prudent Person standard.
The Two-Prong Test
To establish negligence per se, the plaintiff must prove two mandatory legal requirements:
Class of Persons: The plaintiff belongs to the specific class of persons that the legislature intended the statute to protect; AND
Type of Harm: The injury suffered by the plaintiff is the specific type of risk, accident, or harm that the statute was enacted to prevent. [ Safety Statute Violated ] + [ Plaintiff in Protected Class ] + [ Harm of Intended Type ] = Negligence Per Se (Duty & Breach Established)
Procedural Effect of Negligence Per Se
Majority Rule: An unexcused violation of a qualifying safety statute conclusively establishes Duty and Breach as a matter of law .
Examiner Trap: Negligence per se does not establish complete liability! The plaintiff must still independently prove Cause-in-Fact , Proximate Cause , and Actual Damages .
California Rule (Rebuttable Presumption): Under California Evidence Code § 669 , a statutory violation creates a presumption of negligence. The defendant can rebut this presumption by proving they acted as a person of reasonable prudence desiring to comply with the law would have acted under the circumstances.
Statute Inapplicable: If the plaintiff fails to satisfy either prong (e.g., the harm was outside the statute's purpose), negligence per se is rejected. The plaintiff must proceed under the ordinary common-law Reasonable Prudent Person standard.
Recognized Statutory Excuses ( Restatement (Second) of Torts § 288A )
Even where the two-prong test is satisfied, a statutory violation does not constitute breach if the defendant establishes a recognized excuse:
Greater Harm / Safety Necessity: Compliance with the statute would have created a greater risk of physical harm to the actor or others than non-compliance ( Tedla v. Ellman , N.Y. 1939 — pedestrians walked on the right side of the road in technical violation of a highway statute because heavy traffic on the left made compliance suicidal; held excused).
Incapacity / Impossibility: The actor was physically incapacitated or unable to comply despite exercising reasonable diligence (e.g., driver suffers a sudden, unprecedented heart attack; driver's brakes fail suddenly despite flawless professional inspection that morning).
Sudden Emergency: The actor was confronted with an emergency not caused by their own prior misconduct.
Reasonable Ignorance of Operative Facts: A tail light burns out unexpectedly while driving at night without the driver's knowledge.
4. Master Comparison Matrix: Standards of Care Across Actor Categories
Actor Category Governing Standard of Care Role of Custom Impact of Personal Characteristics
Adult Layperson Reasonable Prudent Person under circumstances (Objective). Admissible, but not conclusive ( The T.J. Hooper ). Mental deficiencies ignored; physical disabilities incorporated.
Mentally Disabled Adult Standard of ordinary, reasonable, mentally stable person. Admissible, not conclusive. Mental illness, low intelligence, and brain injuries provide no excuse .
Minor (Child Activity) Reasonable child of like age, intelligence, and experience. Evaluated within child's peer group norms. Subjective attributes (age, IQ, experience) explicitly adjust standard.
Minor (Adult Activity) Full adult Reasonable Prudent Person standard. Evaluated under adult community customs. Child standard extinguished; judged strictly as a full adult.
Professional (Doctor, Lawyer) Knowledge, skill, and care ordinarily exercised in good standing. Conclusive as matter of law ; sets legal benchmark. Specialized training raises standard; geographic standard applies.
Emergency Actor Reasonable prudent person reacting to sudden emergency. Evaluated under emergency conditions. Only available if actor's prior conduct did not create the emergency.
Statutory Violator (Negligence Per Se) Specific conduct mandated by penal safety statute. Statutory mandate supersedes community custom. Replaces RPP standard unless statutory excuse is established.
- 5. Practical Exam Hypotheticals & FYLSE Traps
- Trap Scenario 2: The Intellectually Challenged Driver
Hypothetical: Simon, an adult with an IQ of 70 and severe cognitive processing deficits, obtains a driver's license through an administrative clerical error. While driving down a suburban street, Simon spots a ball rolling into the roadway. Simon concentrates intensely and attempts to apply the brakes with all the intellectual power he possesses, but his sluggish cognitive processing causes him to react two full seconds slower than an average driver, striking a parked car. The car's owner sues Simon for negligence.
Analysis: Simon will argue that he exercised the absolute best judgment and reflexes of which his personal mind was capable. Under the common law, this defense fails completely ( Vaughan v. Menlove ). The RPP standard is strictly objective. The law does not tailor the standard of care to Simon's individual mental infirmities. He is held to the standard of a person of ordinary mental capability and reflexes, and is liable in negligence.
Trap Scenario 3: The Technical Highway Violation
Hypothetical: Brenda walks on the right-hand shoulder of a rural road at night facing traffic. A municipal ordinance mandates walking on the left shoulder. However, the left shoulder is completely submerged in three feet of freezing water from a recent flash flood. A speeding motorist drifts onto the right shoulder and hits Brenda. The motorist claims Brenda is contributorily negligent per se for violating the shoulder ordinance.
Analysis: Under Tedla v. Ellman , statutory violations are excused where compliance poses a greater danger than violation. Walking on the flooded left shoulder would have subjected Brenda to immediate freezing water hazards. Brenda's technical statutory violation is excused, defeating the motorist's defense of contributory negligence per se.