Xrayalpha
I have no doubt whatsoever that the teaching is wrong, most of what I see taught at flying clubs is rehashed Gypsy procedures and limitations.
Lycoming do publish a shut down procedure I have never seen it carred out by a civil flying club.......... The RAF however do use the procedure writen in the Lycoming SB, I am guessing they are the only people who have bothered to read the technical data.
I have no doubt that there are still instructors reeling out the same rehashed Gypsy stuff for Rotax engines.
I doubt the prop bolts are the issue with the Rotax, I would hazard a guess any damage would result in the reduction gearbox or clutch.