Well the explanation of voltage travel was a little off, but main board fried as expected.
It really entered at the motor and exited at the compass that is strapped to the bottom of the plastic landing gear. This would have been the path of least resistance and would have avoided the battery since the motor is connected to the main board, and the compass comes off the main board.
As for the idea of a lighting rod on the top, the very top of the phantom has the GPS antenna and would probably travel into the main board that way also. And the phantom GPS receiver is ceramic s it probably would be destroyed and shattered.