It could be something in the inis like you're thinking already.. however I'm not into inis so I can't help you much there... HOWEVER, from a graphical point of view it seems like the infantry's firepoint bone is attached to its muzzlefx bone... or something similar... That could explain the fact that it flashes on and off quicky as the infantry fires.
Following this hypothesis, the angle the shot is showing could be cause by the firepoint bone being twisted out of alignment (similar to how people tend to break turrets when they first start making generals units.. because the pivt point isn't aligned properly).
Now don't ask me how any of that might have gotten flubbed up.. it might be all normal for the model, but since you're doing something different it might hace started being more obvious. Either way, this is all conjecture and I'm expecting someone to tell you how to fix it in teh inis.. but just incase keep this in mind
