jugofpropwash: "You really believe that in this post 9-11 world, 200+ passengers are going to calmly sit there and allow a couple hijacker/terrorists access to the area, especially when there's a FA standing there screaming "Stop them!"??? "
A mechanic could have been riding along, troubleshooting something in the E&E bay. Some airlines allow this. It can make the passengers nervous, but as long as he has on airline coveralls, they wouldn't be very alarmed. Maybe such a mechanic was "in on it", or maybe his screwdriver slipped, frying some of the electronics, starting a series of events that led to the disappearance of the 777.