Colditz?

[snowball]

Hi,
My grandfather, Thomas William Reynolds, was a lieutenant in the 7th Battalion the Royal Norfolk Regiment, captured in 1940 in the retreat to the French coast.

Now, the published records have him spending the rest of the war at Oflag Rotenburg Fulda but my mother says he told her he had passed through Colditz at some point and had met Douglas Bader there. I've no reason to disbelieve this, but wonder how I might be able to nail it. There was also some suggestion that he'd ended up in Colditz after trying to escape from somewhere else. Any ideas?

I've also got some some supplementary questions!

1. Why would someone enter a prison camp as a lieutenant and emerge at the end of the war as a major (as he did)? Was that unusual?

2. If you were mentioned in despatches (as he was in 1945, prior to liberation), would that suggest that you had been involved in some sort of escape attempt.

Thanks

Rob