Well, crash sites of RAF aircraft are a little bit of a pain, indeed. Have you consulted Cas Rep AIR 81?
I would suggest o try to work out course of events that day, based on ORBs and PCRs, routes, engagements, it often allows to sort out things.
You can search PCRs by date, see this. Interestingly, Giermer claimed his enemy baled out.
https://discovery.nationalarchives.g...ils/r/D7445504
https://discovery.nationalarchives.g...ils/r/D7445664
https://discovery.nationalarchives.g...ils/r/D7441361
https://discovery.nationalarchives.g...rtments=Refine
I would gladly do that myself, but right now I am in no position.
Franek