The guy I mentioned who ruined the pilot truck and pilot of his gs4 was tripping the circuit breaker on the PM42, and he probably didn't hear that tiny relay clicking, and of course rather than back it up from where it stopped, he thought hand-moving it forward some would magically make everything okie-dokie.
And when the damage was done, rather than take his train off so other a could keep running, he left it there and also decided to work on the engine right there on the module.