I think robkarrob said it well. As far as a lighted trigger pull is concerned, if you modded it or had it lighted, and it went off accidentally during handling, the heck yes, you are going to be in trouble. If you've shot it at someone, you didn't shoot them any more or less because of the light trigger (this assumes you actually intended to fire), so it shouldn't make much difference; it's the circumstances of the shooting that matter.

Now, adding a higher capacity magazine, and emptying same into an individual, would/should be frowned upon.