I run the AR9000 in a Bobcat, the RX is 4 inches from the ECU, 6 inches from the fuel pump, 1 remote RX is in the rear of the hatch, 10" away and the other is in one wing 20" away without any issue, including logging every flight with the flight log.
to the casual observer of this crash (me, and im very sorry for the loss!) could the lighting system be at fault? were range checks done with the lights on? do they take power from the RX? are they common grounded if not? static build from carbon lamp mounts holding metal lamp holders? light wires next to servo and RX leads?

Kirk