For an obvious example 5:33 on the video. A bigger guy, An R6? comes into the turn, he spooks off the peg touch and brakes, standing the bike up.

If the suspension was better set up he may have not compressed the suspension so much in the turn. It surprised him and his SR took over.
If you listen on a few of those you hear the scrape before the event. So yeah you can say rider error 100% of the time because whether it's suspension set up,tires or rider skill it's still upon the rider but I think what Neal was saying is that a properly set up bike with proper tires makes a difference.
A lot of people with poor skills enter the turns and get into trouble. As soon as you're off throttle in that turn you unload the rear wheel.
Many of the bikes low side right after there is an upset that takes throttle off the rear. Some seem to just instantly loose traction(tires?) at the rear.
I don't think anyone disagrees with the fact that if the victim wasn't standing there in the first place the rock wouldn't have fallen on him. Lol! So again ultimately, the rider.
Would I do what I do on BT-020's what I do on BT-016's or S20's? No!
Here are some riders that even though they are faster through the same turn in the OP video, are not losing control. They would be considered carrying too much speed if they lost control. No?
Cross-Plane R1's on a foggy Saturday - YouTube