Thanks for the "no blame in an AAIB report" clarification.
People seem to be saying that the problem with this move is that private pilots don't know where to look or what to expect, but again my attention is drawn to the fact that the Yak pilot didn't do what was expected - he turned left instead of right. (Just so happens it was over his house, though of course this was probably just a coincidence.) So even if people knew where he should have been based on the radio calls he made, he may well not have been there. Again, maybe I missing something here.