is to be apportioned...
Mr O'Grady, in Mackay v Moore and Workcover  NSWWCCPD 26 at  et fol.
"Section 22 was considerably amended over a period and had a chequered history in the Court of Appeal, in part, from the use of the term "˜apportioned' in that section. It was not until the decision of that court in Sutherland Shire Council v Baltica General Insurance Co Ltd (1996) 39 NSWLR 87 that section 22 was acknowledged to have the effect which Parliament may be thought to have intended for it. The leading judgment in that case was given by Clarke JA with whom Priestley JA and Hunter A-JA agreed.
His Honour said at 97 and 98:
'... I do not think that there is any impediment to my acceptance of the view that the common law test applies and that the relevant inquiry directs attention to whether the injury caused or materially contributed to the incapacity."
His Honour went on to say the following at 99:
'It follows that I agree with Burke CCJ's conclusion [in Wilson v Blayney Abattoir County Council (1995) 12 NSWCCR 509] that a trial judge's initial task is to determine the liability of an employer or employers to pay compensation to a worker. If the worker satisfies the test in a case where there are a number of work injuries and apportionment is sought the trial judge is then to apply the s 22 test and that test will be satisfied if incapacity resulted partly from one injury (presumably the injury which led to the finding under s 33) and partly from another or other injuries.
"While, therefore, I disagree with Burke CCJ in his description of the primary test of causation I do agree with his view that there is a two-stage process of when apportionment is sought'.
Thus, in my view, the whole of the liability falls upon the employer when relevant injury is found and the provisions of section 9A and section 33 are satisfied. It would be open to her to seek contribution from other employers however this, in my view, does not affect the entitlement of the worker to receive compensation in full from her":