The High Court has now heard argument concerning this important (potentially ground breaking) decision and we are now in the Court’s hands, for their decision.

The transcript of argument can be found here.  Although reading the transcript is not the same as hearing 1st hand, it seems Bret Walker SC had a torrid time, at least from some members of the Court!  

Interestingly, and this is close to a common concern in medical negligence claims, emphasis was placed by him on the capacity of the negligent party to know the information from which firmer conclusions about whether "A caused B" could be drawn.  It is often the case in medical negligence claims that when it is difficult to prove whether negligent medical care caused a particular bad outcome, that frustration is felt that the answer to such question would be known with certainty – if only the negligent care hadn’t occurred (eg if the negligent failure to diagnose the breast cancer hadn’t occur, we would have known whether there was or was not lymph node spread etc).

It seems to me that at least the more outspoken members of the Court during argument, expressed considerable scepticism at the approach of our Court of Appeal, in accepting that the Plaintiff’s exposure to asbestos had contributed to his lung cancer, even though at least some evidence suggested it was 100 times more likely his cancer was a consequence of his smoking.

It also looks to me that the Court may be contemplating narrowing the traditional degree of contribution from negligent (or other tortious) conduct to an injury, for liability to arise.  

Traditionally, enough was shown if negligent action made a "material" contribution, which has often been accepted as met, when the contribution was more than negligible.  

in other words, if the Court accepted there were multiple causes for injury or illness, damages would be awarded if one of such causes was due to negligence (even if it was a minor or secondary cause – and even if it was likely the injury/illness may have occurred even if no such negligence occurred).  Further (and this has always been the difficult part to this, for me conceptually!), liability would then be for the entire consequences of the illness.  There would often not be a substantial reduction in the damages awarded, for the chances the same outcome would have occurred, even if the negligence had not occurred.

From my reading, several members of the Court were grappling, during argument, as to whether for a contribution to be ‘material,’ and so liability and damages follow, a greater extent of contribution should be required.

It will be interesting to see how the dynamics of argument translate into the Court’s decision.

As a footnote, have to say I liked Justice Gummow’s comment, when the submission was put that deciding whether a factor was or was not a cause of disease, was a matter of ‘logic,’ that:

"Logic itself is a house of many mansions"