That is possible, but it takes fairly high voltage to arc across even a small air gap. The electrodes would have to be VERY close together. But, if they were touching, that would short the motor wires and cause substantial ESC heat, if not immediate shutdown.
According to
Wikipedia, it takes about 30,000v/cm to arc across air. I don't know if the induced feedback signals can spike high enough to get to that point.
Interesting though.