I saw it live from the same angle--I'm actually in the EN video so the person filming must have been right behind me. I have no earthly idea how she stayed up. The horse vanished in a wall of water, like it had done a huge belly-flop, then rose out of the waves with Jessica clinging to its neck. The best part was that she fist-pumped to the crowd as she galloped away.
I watched in FEI TV. The shot they showed was straight on and pretty close up.
What saved her was that the horse went absolutely straight like a cruise missile, LOL. It appears that his head for sure and most of his neck at least go completely under water, then somehow he just rises up and regains his feet. No tipping at all to one side or the other, just a straight ahead swim LOL.
I have been surprised there hasn't been more photo's posted and no video from the shot that I saw. I'll call my computer pro son and see if there is a way to get the video off the FEI VOD and post it. It was fabulous.
They weren't showing it live and the British guy doing commentary said they were going to go to her at the water as he was being told it had been quite a splash.
I was behind these people in my little red mobility scooter and it was thrilling seeing them come out of that huge splash. All of us were cheering and high fiveing. The horse and rider were very brave and "kicked on". The horse was having a great time and they probably enjoyed the refreshing shower.