This is a tough one because as anyone here who's a hockey parent knows there's really no way GM can help you if a player doesn't leave. Officials are supposed to escort ejected players off the ice but if (s)he doesn't go the only thing you can do by rule - from what I've found with a quick search, at least - is give the player a game misconduct. All that means is (s)he is affected for the next game(s). I guess you could call a delay of game penalty which would punish the remaining players on that team but if someone doesn't go you pretty much have to wait.
In our sport at least you can get an AD, security or other administrator out there to help you...especially since they don't have to be wearing skates.
And Jeff, North American professional hockey is the only branch of the sport that allows fighting without an ejection
. Any other level - and anywhere else in the world - you're done.