Res Ipsa Loquitur

Thursday’s Class Rescheduled

10:30am in the Robinson Moot Courtroom


How does a plaintiff normally prove duty and breach?

D was legally obligated to do X.

D failed to do X.

Therefore, D breached their legal duty.


Detailed version

D had a duty (to the plaintiff) to exercise reasonable care under the circumstances.

Reasonable care under the circumstances was X, because of - foreseeability, - reasonable person standard, - custom, - statute, - or hand formula.

D failed to do X, therefore D acted negligently / breached their legal duty to plaintiff.


What’s so special about res ipsa?

If res ipsa applies, plaintiff can prove duty and breach without establishing a standard of care.


Two requirements for res ipsa to apply:

  1. Harm results from. . . ?
  2. Defendant was. . . ?

Two requirements for res ipsa to apply:

  1. Harm results from the kind of situation in which negligence can be inferred
  2. Defendant was responsible for the instrument of harm

Case Recap

Byrne v. Boadle: “The Falling Flour Barrel”

Larson v. St. Francis: “The Falling Armchair”

Connolly v. Nicollet Hotel: “The Chaotic Convention”


Why Allow Res Ipsa Loquitur?


Why Allow Res Ipsa Loquitur?

  1. Probabilistic rationale
  2. Asymmetry and fairness justification

McDougald v. Perry


Ybarra v. Spangard


Ybarra v. Spangard on Remand

- Plaintiff’s expert and court-appointed expert testified that the injury was traumatic in origin and not the result of infection.

- Defendants each testified that they saw nothing occur which could have caused the injury.

If you were the trial judge conducting a bench trial, what would your verdict be?


In-Class Exercse for Res Ipsa Loquitur

You are deciding a case as an appellate court judge.

Organize your notes according to the CREAC method:

  • Conclusion
  • Rule
  • Explanation
  • Application
  • Conclusion