SUPERMNNN,
The transponder is located on the aft center pedestal. I fly 757's and have to make a conscious effort not to use that area as a brace while getting in and out of the seat. Even after 10 years in the plane, it's easy to put your hand down there and possibly change the transponder or switch it off. The rotating switch doesn't take much to move. It wouldn't suprise me that those untrained savages flailed about during the struggle and manuevering and somehow change several switch settings. Who knows, maybe they even cycled the generators on and off on the overhead panel while punching buttons.
later