I met an ex FAA pilot once. He was taking off in a Martlet and decided to do a similar thing.
Apparently you unlatch a lock and then wind the gear up manually. He unlatched it but there was still a lot of weight on the wheels and the winding handle flew out of his hand as the gear retracted itself!
I also seem to remember a Tornado doing a similar thing a few years back but he got away with it.