How on earth can this happen? Looks like he hasn´t locked the straps correctly.

Backpack Girl is unmoved by your impending pain.

I think the spot is Lake Silvaplana, St. Moritz, Switzerland, a very nice place with an unforgettable landscape and a more unforgettable icy cold water

well, if you've looked at the gear some people take out, you'd say meh...

three ways I see this happen easily.

1. riders did not install the harness properly (spreaderbar or tightening belt)
2. belt snapped (old worn)
3. spreaderbar connected the old way twisted the hooks out of the spreaderbar loops, and released the harness.

I've had a strap break on my harness before and would bet that's what happened here.

I've ripped the stitching before on my harness. First you feel the lower side peel away, and you are hanging by only the top side, but that quickly peels away too. I sewed it back together with a sewing awl, still holding.

I have to say, good job on the bail, he was upside down, managed to figure out his harness was failing and was able to kick off his board right before impact. Those falls hurt a lot more when you are still on the board.

Until now I have used an old "windsurfing hawaii" waist harness and preferred it to anything else.
It's a simple waist harness with a padded inner belt behind the spreader bar.
It has a single wide strap threaded through both ends of the spreader bar, sewn to the harness on one side and threaded through a large ladder-lock buckle on the other side. Leash clips to the end of the spreader bar.
It stays put ok, but can slide enough for toeside/surf use.
I liked the fit, durability and simplicity - you almost can't put it on without visually checking everything you need to rely on.
But it's about done in by wear.
Is there anything out there comparable I wonder ?

almost happened to my friend yesterday on a 2012 harness - he had installed the spreader bar clips backward (facing in instead of out, as they should have been on this harness). luckily the strap that keeps it from riding up held it on until he could fix it. happened 2 or 3 times before we realized what the problem was haha, would not have been a good way to break in the brand new kite

Had that happen to me in 2002. The stitching let go on my nearly new harness. The harness acted as an anchor as the kite few away in neutral position. The kite landed itself almost a mile down the beach.

Pretty crazy feeling watching your kite fly away in neutral position while your a 1/4 mile off the beach. Wind was dead side shore.

I ended up getting in the car to chase the kite down.

I had that harness-as-anchor thing happen to me too when my harness broke off earlier this year, but in my case it was a good thing as it allowed me to catch up with my runaway gear. The wind was cross-off, so at first when my harness broke off I thought that it was definitely going to be bye-bye to my new kite and bar... However, the kite quickly crashed in the water and then the harness acted like a drag anchor in the water behind it, slowing down the escaping kite. The harness was perhaps 25 meters downwind of me, submerged just undeneath the surface of the water as it was getting dragged downwind by the kite. I saw that it wasn't moving very fast, so I figured I had this one chance to get hold of the harness & bar combo before the kite and everything sailed out to sea. So, lying on top of my directional, I made a mad paddling dash for the harness. It took a minute or so but eventually I caught up with it and could secure the kite That was a great feeling, let me tell you. With the wind blowing out to sea, there was no way I'd gotten that kite & bar back otherwise.

As for what happened to the harness, I obviously took a close look at it once I had self-rescued everything back to the beach. It turned out to be the stitching that had given away. There had been no indications beforehand that the harness was about to break (the stitching that ripped was between the outer shell and the inside lining, so to speak, so any pre-existing damage wouldn't have been visible). The harness was a Dakine Pyro 2008, used for about a year. From what I have read later, other Pyro harnesses from that year have failed in similar manners. Damned shame, cause that model & year is the most comfortable and light harness that I've found.

The harness broke when I made a bottom turn on a small wave. There was obviously some force on the harness at that point, but it must have been on the verge or breaking for some time before that.

The windspeed was only about 22-23 knots. Had it been stronger, I doubt that I'd been able to catch up with the kite in the water.