Via TMZ Sports: The fan says Mike cussed him out and challenged him to a fight saying, "We're gonna do this man-to-man" and "Meet me outside!"
Cops were called but Mike was gone when they arrived. They spoke with employees who said Mike did cuss but didn't pose a real violent threat.
Surveillance footage shows Mike trying to walk away from the fan and sit at a table in the back -- before eventually changing his order to go ... and leaving.
Nobody has a clue who this guy is and unless he was sitting in the restaurant in full uniform this fan is probably the only person who would recognize him. This dumb ass turned away his only fan and spent twice the energy not signing the autograph as it would have taken him to sign it.
What a dick.