Seems to be a visual bug. I was quite sad to see Tym's vet 2 AT gun crew stuck while retreating and hence to be dead soon, but the axis troops swarmed over them without shooting at them.
Tym told me they made it off on his screen, but not on mine, or something like that. The crew was gone from my tac map though.
I had 3 of them, now I only have 1 vet 2 at gun (i had 3)
I lost 4 vet 2 units to some guys who were vet griefing
but anywho.
Yeah, its' a visual bug. What happens is say you retreat a full at gun, 2 of the guys will stay there but one will actually run away, ditto any type of support weapon. To make sure that this is the case, when you see this, check the tac map and you should see the icon running away (which is hard to see by the enemy) and they're not actually invisible, its just one guy and the others are "stuck"