Well no, I think Stath was thinking it's some kind of model mistake which can't be acceptable in such well polished game, that it was not intended to look like this.
But actually that looks great I'd say. I mean a weapon will still shoot if it has ammo (like fuel in this case or some plasma thing it shoots, whatever...) and if it's trriger was not released. Firebats and Marauders have the weapons attached dirrectly to their arms,so I believe if they'd dye thier weapon would still keep shooting... well maybe except for Marauder, he shots explosives and explosive shooting weapons never ever are full-auto...