That's a good achievement for him as the person who gets red card the most (3 times) in Serie A this season, more than the players lmao. He always knows how to amuse and entertain everyone, even when he doesn't intend to. But I didn't know his statement about the place that 4th referee from and if he really said that, then I think strict and firm actions are needed toward him. FIGC is trying so hard to keep Serie A clean and if there is any baseless accusation about them and the league, they must do something.
I think a red card (and subsequent absence from the next game) is enough for punishment. The fact that Mourinho talks a lot is part of the show (and actually it's not so bad for football as a business) and it seems to me that if the functionaries are serious about his every word (even unfair) then this will cause more suspicion and rumors of foul play , referee conspiracy, etc.