SANTA CLARA, CA - OCTOBER 07: Head coach Kyle Shanahan of the San Francisco 49ers speaks with referee Shawn Smith #14 prior to their game against the Arizona Cardinals at Levi's Stadium on October 7, 2018 in Santa Clara, California. (Photo by Jason O. Watson/Getty Images)
SANTA CLARA, CA - OCTOBER 07: Head coach Kyle Shanahan of the San Francisco 49ers reacts to a play against the Arizona Cardinals during their NFL game at Levi's Stadium on October 7, 2018 in Santa Clara, California. (Photo by Jason O. Watson/Getty Images)
HOUSTON, TX - OCTOBER 07: Referee Bill Vinovich #52 looks at the Microsoft Surface as he reviews a play during a football game between the Dallas Cowboys and Houston Texans at NRG Stadium on October 7, 2018 in Houston, Texas. (Photo by Bob Levey/Getty Images)
DENVER, CO - OCTOBER 1: Head coach Vance Joseph of the Denver Broncos talks with a referee during the fourth quarter against the Kansas City Chiefs. The Denver Broncos hosted the Kansas City Chiefs at Broncos Stadium at Mile High in Denver, Colorado on Monday, October 1, 2018. (Photo by Eric Lutzens/The Denver Post via Getty Images)
PHILADELPHIA, PA - OCTOBER 07: Referee Walt Coleman (65) confers with Field Judge Greg Gautreaux (80) and Line Judge Mark Stewart (75) during the football game between the Minnesota Vikings and the Philadelphia Eagles on October 7, 2018, at Lincoln Financial Field in Philadelphia, PA. (Photo by Andy Lewis/Icon Sportswire via Getty Images)
