My general rule is...
I'll pull anyone shooting at players they should know are elminated. I have actually seen a player lose a mask during a game because they got bonus balled in the back of the neck, they put their hand up behind their head to protect their neck, and the glove cought on the goggle and pulled it off when the hand was removed.
Rules aside, bonus balling is stupid. I you're shooting at a dead player, that's paint you're not shooting at live players, and attention you should be paying to something else. Bonus balling isn't just a lack of maturity/sporsmanship, it's indicative of player who thinks it's more important to bully other players than play the game, and that's kinda sad.
One more note about how I ref overshooting as far as bunkering goes: I instruct players to stop shooting when they know they've marked the other guy, and if they're the bunkeree, to turn their back to the player coming to bunker them. If you shoot at a player, hit them, then get shot, then shoot them 20 more times, I'm going to pull both of you. If you shoot the player, then STOP shooting, then get shot, then I know to pull and possibly one-for-one the other guy.
Another situation is you get mugged, turn, and light the guy up the same time as your teammate lights the guy up. Frankly, I'm probably going to assume the hits were from you, leave the other player in, and pull you and your teammate - if you'd walked off, it'd at least have been an even trade.
Point is, shooting dead players just makes it harder for the refs to tell that you got them first, and makes it more likely you get pulled even though you had the first hit. I can't say I feel the slightest bit guilty as an official if a player gets pulled because they don't know when to lay off the trigger.
- Chris