I don't recommend doing engine outs by
pulling the mixture knob either. But people do it and usually get away
with it.

Actually, on carbureted engines the mixture cut is the safe way to do
it, and it's the people who use the throttle who are taking a risk -
the very real risk of fouling plugs and building carb ice (carb heat
may not be terribly effective at idle power) rather than some
mysterious and unexplained risk of the engine not starting again.

On injected engines, it's not so simple - there vapor lock is a real
issue so the correct procedure is a throttle cut - but one must pay
VERY careful attention to keeping the mixture VERY lean, lest plugs
foul and full power is not availabe just when you need it most.

Michael