[tempest]

It's hard to say exactly why it happened in that instance. Possible causes: Halyard is led to the winch at an angle instead of straight on. Too many wraps. Initial wraps were loosely laid and slid under when tightened. Were you tailing it? or self tailing? if the former, you want to come straight off the winch at the height of the last wrap.

It happens.. no fingers were lost = good day