Whatever the initial cause the aircraft's angular momentum was soon greater than the machine control and/or pilot's ability to counteract.
I had this happen to me once, in a tail-dragger. It was a nice day but with reasonable cross-wind, I came in a little faster than normal and upon landing the a/c wanted to go left, nothing I could do would stop that (this a/c has notoriously poor brakes) so left we went. Fortunately for my ego I was not going too fast, nor the turn too sharp, so it ended up being a nicely proscribed turn into a not inappropriate area, and I don't think anyone was watching anyway. However that I clearly remember it to this day is testament to the significance of the moment.
In my case I'm reasonable sure there was nothing other than insufficient ability of the controls (wheel brakes and rudder - it was a castoring tail wheel) to cope with the angular momentum of the machine. What I see in this video appears similar to my experience - although it's possible there could be an issue with the pilot's knowledge/ability around opposite lock correction and/or momentum, which could have an effect.
With regard to the latter, I wonder if there's a place to learn a little about this during training? In my case the knowledge had been learned during a misspent youth with lots of cars/motorbikes coupled with mud or gravel, however there will be people who've never had the experience and may simply not know how to cope, and foot control is somewhat different than wheel anyway...
FP.