This hasn't happened to me, I'm just guessing about what advantages an electric PS might have vs. the much cheaper/simpler belt driven pump...
I'm thinking more along the lines of an engine stalling... I would imagine even with push button start/stop, it would remain in ignition mode should the engine stall... And I'm also just guessing the electric pump would still receive battery power and would benefit an emergency situation like the engine turning off for some reason while traveling @ 60 MPH in rush hour traffic...