While damaging an opponent just before they die of the enviroment properly gives you credit in any other mode, in Gun Game it doesn’t advance you to the next gun in the list, even if it properly counts it as your kill.
This currently is very abusable, since you could just throw yourself out of bounds/into fire/acid while you’re being shot in order for the other player to not get advanced to the next gun, plus it respawns you with full health as if nothing happened.
This also could apply to weapons that can inflict self damage (mainly explosives), as in you could just shoot down and die by your own weapon to escape a tight situation; but in this case, it could work like a 3 strike system, where if you die by your own explosives 3 times in a row for that weapon, it should penalize you and set you back a gun.
Why a strike system instead of penalizing you out right? Because it is very likely to be mashing into the transition to the next gun and accidentally die.