Corrected entry: At one point while the group is trying to bring back Rachel the power goes out and they freak as they can't defib. However, this is a portable defibrillator used by ambulance personnel which has its own power source. The only trouble they might have is they can't see as well.
lionhead
28th Feb 2011
Correction: The defibrillator wouldn't work because David was asked if he charged the batteries, and he indicated he didn't.