use an eventhandler friend addeventhandler ["killed",{[_this exec "somescript.sqs"}]
then in the script;
_friend = _this select 0
_messages = ["JOHNNNYYY!!!!","DAMN ALPHA IS DOWN","JOHNNY IS HIT"]
_ran = random (count _messages)
_ran = _ran - (_ran mod 1)
player sidechat format ["%1",_messages select _ran]
not guarenteed as i havet got OFP in front of me