Typical human; we just love conspiracy theories especially when the circumstances are a bit hazy.
Personally, I think Miller's plane was just at the wrong place at the wrong time.
I even heard (well, read) that the plane flew under a group of bombers returning from a bombing mission. Apparently, a few bombers dropped their loads in the Channel (we all know a WWII plane didn't land wih armed bombs in its belly, right?) as they didn't had the chance to drop them on their targets.
One of these bombs (or several) must have hit the plane underneath.
That's just another theory.
I don't believe the French widow and that prostitute story at all (smells like revisionism to me!).
Erwin (a BIG fan of Glenn Miller's music )
PS: Not in race for ranks either, wanted to remain Sergeant.