Any further issues Blair? Have you managed to isolate it to the coin door pcb?
If not - I reckon next step is to locate the CPU board plug for direct switches and remove (game off before hand)....See if problem happens again..
That should eliminate any physical wiring issues between coin door and CPU board.
From my WPC games - my understanding of B.R & Cap issues generally causes the game to actually reboot - ie same as switch on / off
If switches are activating on their own (ie flippers) & coin door test buttons there would be something screwy going on on CPU board in /around switch matrix and direct switch IC's
