Burk later worked as an NFL official as a back judge (now field judge), wearing uniform number 63. He worked the game that saw Joe Kapp of the Minnesota Vikings tie his record for seven touchdown passes in one game in 1969 vs. the Baltimore Colts. Burk was also the back judge in the famous 1972 playoff game between the Oakland Raiders and the Pittsburgh Steelers. That game, played in Pittsburgh, featured the play that came to be called the "Immaculate Reception". From his position as back judge, Burk was the first of the officials to signal a touchdown.
During a 1973 game between the Chicago Bears and Denver Broncos, Bears coach Abe Gibron can be heard chewing out Burk throughout the contest. Gibron was miked for the game by NFL Films, and the footage was released by NFL Films Executive Director Steve Sabol in 2001.
