Smoking weed unsafe? Chances are all that will happen is the guy will forget to flip his safety off during play :smack: .
The real question is why at a game? People will be offended and their opinion will change of you greatly, one would think the person in question would have known this. I agree that being high at an airsoft game is inappropriate and irresponsible, but let's not call it "dangerous to other players". Anybody with experience in this area will back me up on this, it's more dangerous to have hungover or sleepfucked players than somebody who is high at a game.
*Before I get jumped on by people who haven't read my whole post, my official stance is I disagree with marijuana use during or before airsoft games*