Like I said, it's a matter of degrees.  He could also simply be unaware of the local laws that would affect Kalston, and be coming from somewhere where his weapon of choice was perfectly legal for him to own and use; and the point still remains, there's no way a civilian could be authorized in any capacity to use grenades of any sort. Hell, when the actual military is doing drills, they use dummy grenades.<br/><br/>There's also the fact that he is currently angry, and anger, as I'm sure we all know, tends to hamper ones ability to make logical and rational judgments.