I have just a theory.... if he was wearing a new officer pattern uniform during his officer training (which would have been of shorter duration than it is today perhaps), would he have wanted large thread holes across the upper arm of his uniform once he had graduated? The aircrew rank structure was very new in 1947, and perhaps this was one of the early "experiments" with the badges that was tried. Same for the flying badge: why put on an old standard badge for just a very few weeks and then have to un-pick it before putting on the new one.
The alternative of course is that he just got it wrong with the new AC II badge.