don't give him a warning, it gives him ample time to deploy hard points turn and face you and stick all his pips to shields and weapons
do the cowardly thing and, drop to silent running, sneak round behind him and pop him in the back whilst he his gaffing around with trying to figure out where the letter box is in the station he is heading to
Even better .... wait till he logs in to his Star Citizen account and wait till he gets out his flight chair, walks back down the ship, unzips his trousers, pulls his pants down and sits on the toilet and presses D to dump (you know all that useful stuff in a space sim) ..... then shoot at him