Caroline,
Thanks for your posting, I'm glad that I'm not the only one to make such assertions!
I agree with everything Harry says, the OTU's did have to cope with some very tired old aeroplanes and I'm sure that contributed in no small part to the loss of so many trainee aircrew.
Looking at the loss reports for this particular night, 22 OTU lost three aircraft , as Harry says. What struck me as I read the reports was the fact that all three reported problems with the starboard engine. That is some spooky coincidence.
Now I'm going to really stick my neck out!
Studying the photo of our young man for the umpteenth time and comparing facial features with the crew photo, I believe there is quite a resemblance to the man second from right, i.e. the one I nominate as the rear gunner. If it is not a younger version of him, then it could well be a younger brother, in which case he may not have been aircrew, hence no flying badges and if the photo was taken in Canada, he would not necessarily have worn CANADA flashes.