McGill Faculty of Law: Extra-Contractual Obligations/Torts: Prof. Lara Khoury, 2002-03/Summary by Derek McKee
Novus actus interveniens: If two or more faults caused the same injury, but they did not occur at the same time, the author of the first fault may argue that the second fault broke the chain of causation.
This is rarely used in either system.
However, courts may accept it when the second fault is more serious than the first fault (especially if it is intentional or criminal). Usually, the more culpable the intervening (second) act, the less foreseeable it is for the first defendant.
However, in common law, this use of novus actus interveniens is limited by the concept of risk: If the act of the first defendant creates an unreasonable risk of an intentional or criminal act by someone else, then novus actus interveniens can’t be used (if the second fault was “the very thing likely to happen” as the result of the first fault)
This is based on the idea of foreseeability: if you create a risk, the the second defendant’s fault is more foreseeable.
So, the factors to consider are severity of fault, creation of risk, and foreseeability.
Q. v. Minto Management Ltd. (1985), 15 DLR (4th) 581 (Ont. H.C.). (CB2p157)
Q. was raped in her apartment by Halliday, an employee of her landlord (Minto). Halliday had broken into Q’s apartment using a master key. Three months earlier, another woman in the same complex had been raped. Halliday was subsequently convicted for both rapes. The landlord knew about the earlier rape, but did nothing in the meantime to warn tenants or to control the use of master keys.
Was Halliday’s action so remote from Minto’s fault as to constitute a novus actus intervieniens?
Gray J excluded the possibility of novus actus interveniens on the grounds of creation of risk. He cited Haynes v. Harwood, a British case from 1935, where Greer LJ wrote, “If what is relied upon as novus actus intervieniens is the very kind of thing which is likely to happen if the want to care which is alleged takes place, the principle embodied in the maxim is no defence.”
In common law, medical negligence (but not non-faulty “medical error”) breaks the chain of causation, according to the Ontario Court of Appeal in Mercer v. Gray (1941).
This is based on policy reasons, favouring compensation, allowing the plaintiff to recover from the hospital (deep pockets).
This rule has been criticized in common law:
for policy reasons: In practice, it’s actually hard to recover for medical negligence in common law, so this rule doesn’t necessarily favour the plaintiff.
for theoretical reasons: Why should medical faults be treated differently?
However, if both defendants are doctors, this rule doesn’t seem to apply:
Price v. Milawski (1977), 82 DLR (3d) 130 (Ont.C.A.). (CB2p183)
Price broke his ankle playing soccer. He went to an emergency room, where he was examined by Dr. Murray. Dr. Murray accidentally told the radiologists to x-ray Price’s foot rather than his ankle. So Dr. Murray did not see the fracture, and treated Price for a sprained ankle. When the pain and swelling persisted, Price went to see Dr. Carbin, an orthopedic surgeon. Dr. Carbin did not even look at the x-rays but simply telephoned the hospital and was told that the results were negative. As a result, Dr. Carbin diagnosed Price with a strained ligament. Eventually Price went to another doctor who ordered new x-rays, discovered the fracture, and put the ankle in a cast, but Price was permanently disabled as a result.
Did Dr. Carbin’s fault break the chain of causation from Dr. Murray’s fault?
No. (Both were held jointly and severally liable.)
Arnup JA does not appear to have given any special weight to the fact that Murray and Carbin were doctors. He looked at the case in terms of foreseeability, and held