mercy, safety, surrender is needed. i have been lit up multiple times safetying people rather than shooting them up close, regular players included.
our local field is experimenting with not letting people get to the same bunker, people must be eliminated before advanced to the bunker they are/were in. if a player gets to the same bunker, they are basically resetting the player back to his previous bunker and not allowing them to advance until the player(s) are eliminated. i prefer allowing people to go up to the bunker and slap it twice yelling bunkered or whatever the safety world is.
something another field does that i really like is they closely watch the game (pretty good reffing), they will step in and call the game if only one player is left as everyone is surrounding the player to prevent a painful experience or as the advancing player gets too close. this requires more refs that are vigilant though.