David Joyce was seriously injured when he fell from the back of a van driven by his uncle, Edward O'Brien. This was no innocent Sunday afternoon excursion: they were, in fact, speeding away from the scene of a crime, having stolen some ladders. O'Brien later pleaded guilty to criminal charges of dangerous driving but maintained in the civil suit brought against him by his nephew that their common criminal enterprise was a complete defence to civil liability. In support of that, he (or his counsel) trotted out the old maxim ex turpi causa non oritur actio (loosely translated, 'don't expect to recover if you yourself have been up to no good'). O'Brien's defence was successful in the trial court. Joyce appealed: Joyce v O'Brien,  EWCA Civ 546.
Lord Justice Elias reviewed the authorities on criminal joint enterprise from England and Australia, observing the law has shifted from a rigid position that denies the existence of a duty of care between participants in such an enterprise to a position which recognises that the duty of care 'may remain intact even where the conduct causing giving rise to the injury is in pursuance of the illegal joint enterprise.' The law now also takes both a narrow and a wider view of the ex turpi principle: the narrow view is the civil courts will not compensate someone for injury or disadvantage which a criminal court has imposed by way of punishment for a criminal act; the wider version is that 'you cannot recover for damages which is the consequence of your own criminal act'. The wider formulation gives rise to the question whether the injuries at issue were caused by participation in the criminal joint enterprise or whether the enterprise merely 'provided the occasion for someone else to cause something'. In the latter case, negligence in driving the get-away car might not attract the ex turpi principle -- unless the character of the joint criminal enterprise is such that it is foreseeable that one or more parties to it will be subject to unusual or increased risks as a result of participation. On the facts of the ladder caper, Joyce's own carelessness in taking the risks he did were sufficient to deprive him of the right to recover compensation for his injuries, which in the end were caused by his own criminal acts and his implicit encouragement of his uncle's bad driving. This was not a case to apply some flexibility or proportionality: nephew and uncle were engaged in a crime punishable by a prison term of up to 7 years, not some minor traffic offence.
See also Miller v Miller,  HCA 9.