Over the years I ran into a lot of types that "knew" martial arts that violated the law. They all shared one thing in common. The went to jail.
We had a state Martial Arts Champion here killed by two drunken teenagers. He was not drunk. Many were puzzled by why he did not put up a defense. The two suspects when arrested were surprised at his background and as they said, "how easy" he was.
I've also worked with officers with strong backgrounds in various arts. In practice they seldom if ever used those skills and the matter turned into a wrestling match of sorts with no evidence of trained skills.
With much investigation on the subject, we have concluded a failure to perform ratio that is very high.
Handling a mouthy drunk is one thing, but with strong criminal INTENT of a criminal,and THEIR rules of engagement we have determined a failure to perform is based on mental chemistry that blocks memory and the ability to recall training which occurs in shootings as well. There is no amount of training that can change a genetic reponse to fright.
The rules of criminal engagement are not like in the movies and are not formal, organized or fair.