Same as I'm sure the infamous pic of a SS Grenadier in the battle of the bulge wasn't issued the M1Carbine he is carrying, not my point.
Peter the photographs being referred to are from the Australianwar memorial collection not the opinion of some "expert" writing a book many decades after the fact. Most photos that I am referring are taken by official combat photographers, so yes I have a fair bit of confidence in the source being correct. In addition there are simply just far too many pictures with diggers using Garand's for it to merely be battlefield expedient pickups, not to mention the US troops fighting right alongside may have had something to say to their weapons being plundered.
Having seen with some hilarity the reaction that simply losing a pull though can sometimes generate I can just imagine with a wide smile the reaction from above when a large number of diggers try explaining as to where all their issued No1's had gone. While I appreciate M1's, No 4's or any number of other items quite commonly seen in AWM photo's that were never issued officially to us en mass it certainly doesn't mean it didn't happen in theatre for any number of reasons, it still happens today!
Now if it was Japs using Garand's then your point is well made.