Definitely sad. Sounds like it was preventable.

Sometimes though, stuff just happens on a launch. I still recommend launching with one hand on your QR, just in case. It's hard to find it once stuff starts getting hairy. Very sad story. I would hope we would simply INSIST the person not launch if this was to happen/be witnessed here.
Without using names (guy is gone now anyway), several years ago (5 ) 3 of us insisted our friend not launch his kite in 30+ knots out at the Undertow. He had a 10m Fuel I believe. It was one of those days it nukes ALL day, and he hadn't ridden in weeks and had waited all day. He really wanted to ride.
It was hairy. 2 guys were holding on to him and all three were getting dragged. We realized what a bad decision him riding would be and insisted (against his will) that he was NOT riding that day.

He was PISSED when we forced him to land his kite and bitched about it for days and days and said we weren't his friends.
It sure was nice to have him around tho :P