The "reason" why the chopper gunner doesn't pick you up. Is that they "claim the LZ is to hot (from the zombies)." but in reality they have bets back at base on how long you last.
I think that when you blow a bridge a the timer should go blank and a hoard should attack (unless island cleared or last bridge on multibridge levels) because your blowing a bridge and that makes a lot of noise and in the zombipedia zombies are attracted to noise so its logical that zombies would attack if a bridge explodes.
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