LoL.... it happened to me yesterday.... its a replicateable glitch.
You know how the powerblow cinematic is slightly different if its enough to kill or flings the opponent into a Dangerzone ? Yep that part where they zoom in on the character and you can see these weird water particals moving in slow mo around them....
If you can time the powerblow in such a way that time runs out before the power blow K.O.'s the opponent then all the hit affects for the remaining rounds will occure in Slow Motion.
You must make sure the The round ends and transitions into the next round at the exact moment when the cinematic is at the Slow Motion part of the Power Blow.
In the remaininf rounds all the Hit Effects will occur in Slow Motion but the game will still run at full speed..... even the dirt shuffles around in Slow Mo. Its pretty cool. I got so distracted that Hayate beat me.
I can't watch the Video myself.