49ers Jim Harbaugh, right, reacts as he talks with referee Walt Anderson during a game against the Seahawks in San Francisco, Oct. 18, 2012. (AP Photo/Marcio Jose Sanchez)

Seahawks head coach Pete Carroll reacts to a play against the Vikings, Nov. 4, 2012, in Seattle. (AP Photo/Elaine Thompson)

Panthers Ron Rivera, right, talks with an official, during the first half of a game against the Redskins, Nov. 4, 2012, in Landover, Md. (AP Photo/Richard Lipski)

Titans Mike Munchak talks with side judge James Coleman in the third quarter of an NFL football game between the Titans and Bears, Nov. 4, 2012, in Nashville, Tenn. (AP Photo/Wade Payne)

Lions Jim Schwartz talks to head linesman Wayne Mackie during the second half of a game against the Jaguars in Jacksonville, Fla., Nov. 4, 2012.(AP Photo/Phelan M. Ebenhack)

Buccaneers Greg Schiano, right, argues a call with umpire Tony Michalek during the second half of a game in Tampa, Fla., Sunday, Oct. 21, 2012. (AP Photo/Phelan M. Ebenhack)

Redskins Mike Shanahan gestures during an NFL game against the Panthers, Nov. 4, 2012, in Landover, Md. (AP Photo/Nick Wass)

Saints acting head coach Joe Vitt talks to an official during the first half of a game against the Eagles at Mercedes-Benz Superdome in New Orleans, Nov. 5, 2012. (AP Photo/Bill Haber)

49ers coach Jim Harbaugh, left, with line judge Mark Perlman, center, and referee Bill Leavy, right, prior to facing the Cardinals, Oct. 29, 2012, in Glendale, Ariz. (AP Photo/Paul Connors)

Browns Pat Shurmur, center, argues a call with referee Jeff Triplette, left, and line judge Jeff Bergman in a game against the Ravens, Nov. 4, 2012, in Cleveland. (AP Photo/Tony Dejak)

Packers head coach Mike McCarthy, left, and Aaron Rodgers talk to official Mike Spanier during the first half, Nov. 4, 2012, in Green Bay, Wis. (AP Photo/Jeffrey Phelps)

Redskins Mike Shanahan yells at head linesman Dana McKenzie in the first quarter of a game against the Steelers, Oct. 28, 2012, in Pittsburgh. (AP Photo/Don Wright)