Not being familiar with the controller of this motor, I would guess the system tried several times to start the motor. And, with an open run winding and a high current start winding the resistor over heated and ultimately failed.
I've worked on a wide variety of motors and I can't say I've ever...
I see you're checking case to phase for a possible short, but do you also check phase to phase resistance? The phases should be within ~10% of each other.
Also I've seen temperature related failures where there's a breakdown in the insulation when hot and then looks fine when cold.
If your...
