Medic ≠ a Nazi - Source?

Okay, I have a serious question.

It’s common “knowledge” that Valve apparently stated that Medic was not a Nazi, right? Don’t get me wrong, I absolutely don’t claim that he was, but when and where exactly did Valve say this?

I’ve been looking on the Wiki, Valve forums and several other places, asked around, but nobody could give me an answer or a source for that statement.
(I really hope it’s not just something that has been claimed by the community for years so that it just became an accepted “fact” at some point.)

I’ve only been in the fandom for ~2 years, so maybe one of the veterans knows more about this and could provide me with sources?