If the ref thinks it's clear the player was going for an arm (or other body part) intentionally and not trying to make a play on the ball, then it is a Flagrant 1 foul. That's not the same thing as a player making an attempt on the ball and whiffing. The ref deemed that Mika intentionally grabbed the arm and wasn't playing the ball. And I agree with him – that looked pretty clear to me. Wasn't a dirty play, but it was correctly called a Flagrant 1 IMO. That's how the rule book defines that kind of foul.