As it turned out, he decided that sulking in a back room was better than provoking a confrontation, so I didn't have a chance to apply Aikido in Real Life (tm). Except of course to whatever extent my merely being there helped. And so I don't have any great anecdotes about how brutal a koshinage takedown is for untrained people.
it could have gone bad in another direction. he could have coming out shooting.
a few folks I knew in LEO told me that many of the domestic violent situations were great deal more dangerous. sometimes, the folks, that they came to protect, turned against the LEOs, sort of Stockholm syndrome.