I was doing some casual Player VS CPU match. I used Sarah and chose Christie as the opponent in the Flow Stage in a 5-round match. When the raft was at the edge of the waterfalls and Christie had little health left. I pinned her to the wall with a wall throw and instead of falling down to the Primal stage. Sarah jumped down and I end up back to where the raft was located in the cave for the next round.
I was fighting Akira with Kasumi on the Flow stage. At the end of the final round, we were at the edge of the stage with the raft at the waterfall and I finished him with a throw cliffhanger attack. We smashed through the ground of the Primal stage and ended up back at the start of the Flow stage! So when Kasumi did her winning pose, she was back on the raft, inside. I was shocked to say the least.
I tried reproducing the glitch, but it hasn't worked since.