Great news.

If they had done this to Cassius Marcellus Clay, these criminals would simply be dead for their gross violation of civil rights.

How can a County express regret or even experience it ?

Regret is the un-apology word. It’s weaseley in the extreme. If they accepted responsibility they could just issue a real apology and call it a day.

It is refreshing that they admitted wrong-doing. Often payments are made to victims, but those responsible never have to admit the mistake.

From the article though, I think this line is telling:

"This likely would not have happened if established law had been reviewed and applied prior to the execution of the warrants,"

likely not. They are saying that even if those involved absolutely totally knew and understood the law, there's still a decent chance they would still have done the raid.

I agree that that "likely" is not a good look, but this was written by a lawyer to fulfill a legal obligation as part of this settlement, so I'm not surprised.