I have no idea. I believe it is possible to have seperate briefings for each side, but that isn't quite the same thing.
You could fake it, with a firm injunction in the Briefing to pick only weapons from your own side. (And a list of which is which, so as to avoid mistakes.) When the mission starts a script detects what each player has and if its the wrong thing, it gets taken away and he is left unarmed. Or he gets setdammage 0.