Another full scale story on that very point. Over twenty years ago, a young (21 on the day) Air Force Mirage pilot was celebrating his birthday, and barrel rolling at about 300 knots and a couple of hundred feet over the airstrip at Williamtown, just north of Sydney. He pulled instead of pushing at the end of the manouver, and the biggest piece they found was about as big as a dollar. Just one small lapse of concentration is all it takes.

The cost in model flying might not be quite so dramatic, but it's easy to do.

There was a dramatic shift in Air Force operating philosophy after that incident. There had been more aircraft lost in screwing around than in combat over a couple of wars.