I have had first hand experience on this, and (embarassingly), it was completely my fault. Last summer i blew a landing on a jump and ended up backwards in the water. I'm not sure if the kite looped or crashed and re-lauched, but i immediatley got yanked back up out of the water and deposited well downwind from where i started. I ended up in the path of an oncoming kiter. On hitting the water the second time, my kite crashed with my lines crossing over the other kiter's lines, which caused his kite to also crash. The other kiter and i ended up right against each other, but luckily we did not actually crash (at speed) into each other. With the kite now on the water and not much pressure on the lines, i quickly unhooked from my chicken loop (not using the QR) and held onto it and used the QR for my leash. holding onto the chicken loop, i passed the bar over the other kiter's head so that we weren't entagled if something further went wrong. before i could get myself hooked back in, my kite decided to relauch again and it pretty much just yanked out of my hand. It landed again as soon as i let go and drifted into shore where someone collected it for me. The other kiter was able to re-launch and kite away.
My first concern was to get the two of us separated as quickly as possible. we got lucky that the lines weren't actually tangled, just crossed, and that neither of us was hurt. I released both the CL and the leash right away so that, if necessary, we would be completely separated if i just let go. In the end, not being attached to the leash left me having to chase the kite, but i think it was the right thing to do to guarantee that we wouldn't be attached to each other if either kite re-launched.
1) Leave way more space than you think you might need between you and other kiters (and any other obstructions) when jumping especially, but in general, too. Things can and do go wrong and you cover distances very quickly. I was probably 150 feet upwind and 200 feet left-to-right away from the other kiter (tho heading towards me) when i launched the jump. Obviously, that's not enough when things go wrong.
2) When things go wrong, stay calm, be aware of what is going on around you, and react as soon as possible.
3) Deal with the immediate threat first. In this case, once the lines were crossed, it seemed to me that the worst that could happen was that one or both kites would re-launch while we were attached to each other, so my first actions were geared towards stopping that from happening.