Mahony v Kruschich[1985] HCA 37; (1985) 156 CLR 522



A Mr Glogovic, the plaintiff in a cause of action against his employer, Kruschich Demolitions Pty Ltd, alleged that he sustained injuries on 4 April 1976 when he was employed in the demolition of the old power station at Lithgow. He alleged that his injuries required considerable medical treatment.

Among the medical practitioners who treated him was Dr Mahony.

Kruschich brought a cross-claim against Dr Mahony alleging, amongst other things, that during the years 1977 to 1982 Dr Mahony treated the plaintiff by various medical, surgical or diagnostic procedures and “was negligent in and about carrying out the aforesaid procedures to and treatment of the Plaintiff”.

Kruschich alleged that Dr Mahony’s negligence “caused or contributed to the continuing injuries and incapacities alleged by the Plaintiff and for which he sues the Defendant”.

Kruschich claimed against Dr Mahony a complete indemnity or, alternatively, contribution toward the compensation that Mr Glogovic might be paid.


Where a tortfeasor’s negligent act or omission causes personal injury, “damage” includes both the injury itself and other foreseeable consequences suffered by the plaintiff.

A negligent tortfeasor does not always avoid liability for the consequences of a plaintiff’s subsequent injury, even if the subsequent injury is tortiously inflicted. It depends on whether or not the subsequent tort and its consequences are themselves properly to be regarded as foreseeable consequences of the first tortfeasor’s negligence.

A line marking the boundary of the damage for which a tortfesor is liable in negligence may be drawn either because the relevant injury is not reasonably foreseeable or because the chain of causation is broken by a novus actus interveniens (new intervening act).

It must be possible to draw such a line clearly before a liability for damage that would not have occurred but for the wrongful act or omission of a tortfeasor and that is reasonably foreseeable by him is treated as the result of a second tortfeasor’s negligence alone: see Chapman v. Hearse [1961] HCA 46; (1961) 106 CLR 112, at pp 124-125.

Whether such a line can and should be drawn is very much a matter of fact and degree.

Where it is not possible to draw a clear line, the first tortfeasor may be liable in negligence for a subsequent injury and its consequences although the act or omission of another tortfeasor is the more immediate cause of that injury (cf. Lothian v. Rickards [1911] HCA 16; (1911) 12 CLR 165, per Griffith C.J. at p 176).

Provided the plaintiff acts reasonably in seeking or accepting the treatment, negligence in the administration of the treatment need not be regarded as a novus actus interveniens which relieves the first tortfeasor of liability for the plaintiff’s subsequent condition. The original injury can be regarded as carrying some risk that medical treatment might be negligently given. It may be the very kind of thing which is likely to happen as a result of the first tortfeasor’s negligence.

However, in the ordinary case where efficient medical services are available to an injured plaintiff, the original injury does not carry the risk of medical treatment or advice that is “inexcusably bad” … or “completely outside the bounds of what any reputable medical practitioner might prescribe” … or “so obviously unnecessary or improper that it is in the nature of a gratuitous aggravation of the injury” …or “extravagant from the point of view of medical practice or hospital routine” …. In such a case, it is proper to regard the exacerbation of a plaintiff’s condition as resulting solely from the grossly negligent medical treatment or advice, and the fact that the plaintiff acted reasonably in seeking and accepting the treatment or in following the advice will not make the original tortfeasor liable for that exacerbation.


The cross-claim should not be struck out.

It was neither necessary or possible at this stage to determine whether, and if so to what extent, Dr Mahony had been negligent or whether such negligence had contributed to, or caused the Plaintiff’s injuries.

If Kruschich be held liable in damages to the plaintiff, Kruschich may be able to prove in the cross- action that if Dr Mahony had been sued by the plaintiff, he would have been liable for some of the damages recovered by the plaintiff and, in that event, Kruschich will be entitled to an order for contribution under.

Key Information


High Court of Australia


Gibbs C.J.(1), Mason(1), Wilson(1), Brennan(1) and Dawson(1) JJ.



New intervening act

Subsequent negligent medical treatment

Full Case online:

[1985] HCA 37

Case Citator:

LawCite: Mahony