Yes I wonder if he accidentally went up the wrong valley. On looking at Google Earth that looks possible but also there looks like an escape route at the end of Jerusalem Bay if you bear left, though it may not have been visual at the crash point.
I went up a wrong valley once in the great dividing range and it was not a good feeling when I realized the error, but I had space to do a U turn. I was trained in tight canyon turns using full flap in some blue mountain scud running flights. Your horizon can be fooled by the close hilly terrain.