SS gestapo didnt care about geneva convention.
What makes you say that?
I'll play, how many?
What do you mean, without regard? What do you know about rules of engagement?
go throw your wasp ass somewhere else
It was "legal".
But the gestapo knew they were escaped soldiers. They used the excuse to shoot them.
And yes, just about every thing you saw in that movie actually happened. The only real difference is they combined several real men into a handful of composite characters.
The stuff you saw a dozen guys doing was actually done by a hundred guys.