I know he braked. That's why he crashed.
Situations like this u gotta commit and trust the bike and tires will get u through. He was an experienced rider but came in a little too hot into the corner and panicked. He knew what he did wrong and took complete responsibility.
He locked up his rear brake for just a millisecond while trying to slow down which cause the rear tire to skid. After the brief skid, he freaked out and panicked and rode off.