Just an update on the details of what happened, if anyone's interested, cos I was surprised as hell to learn about this...
I went into work today where I spoke to Rob, and the scary part is that he can remember a lot more of what happened on the beach than I can. I have no memory of getting lifted, dropped 3m or getting dragged along on my butt, or apparently steering the kite towards the water.
I can only remember the kite suddenly jerk downwind as I brought it in to land and my immediate, but failed pull on the release tab, then cut to 3 seconds of what looked like the video from a camera mounted in a soccer ball after a good solid boot, and then sitting waist deep facing the kite and away from shore, finally getting the pin out after about 3 more tries and swearing like a florist about the pain in my arm. I just can't connect the three events, especially with the stuff he told me happened.
The only explanation is that I must have got knocked out

while hooked into an out of control kite heading out to sea - fantastic!
Oh yeah, and work was OK with me wearing thongs.