Yep, true story. I dont know anything about a helicopter, but i was playing with a friend when the whole server was killed for no reason (probably 20-30 people). no fraps at the time.
An IED idea? Timed explosions using a cigarette, fireworks, and matches. Or perhaps dynamite. Just tie the fuse around the base of the cigarette, light it, and wait a few minutes. It could distract zeds and kill/injure survivors.