"I let my emotions, my passion for our football program and the frustrations of the first half of the season get the best of me, and my actions reflected negatively on our program," Christensen said in a statement issued Sunday night.
After Saturday night's game, Christensen confronted Air Force coach Troy Calhoun on the field and questioned whether Falcons quarterback Connor Dietz was really injured when he left the game for one play with about eight minutes left in the fourth quarter and Wyoming leading 27-21. He said the several minutes that trainers attended to Dietz gave Air Force time to strategize the next play.
Air Force ( 3-3, 2-1 Mountain West) scored what turned out to be the winning touchdown when backup quarterback Kale Pearson ran a bootleg in from 5 yards out on third down after Dietz left.
The referee announced that Dietz, by rule, had to leave the game because his helmet came off. At the time, Air Force had all three of its timeouts available.
When the game ended, Christensen was visibly upset as he met Calhoun on the field.
Calhoun described the meeting with Christensen as "probably not a conversation that I'd have with my mom."
In interviews after the game, Christensen continued to criticize Air Force, saying he didn't believe Dietz was hurt.
"In this game, we're supposed to be ethical and that's not ethical," he said.
The incident occurred on homecoming weekend for Wyoming (1-5, 0-2) and on a night when it recognized the contributions of the nation's military. The Cowboys wore uniforms with military camouflage designs and words such as "Honor" and "Integrity" in place of their names on the backs of their jerseys. Christensen wore a camouflage hat.
In his statement on Sunday, Christensen apologized to "Wyoming fans, the Mountain West Conference and the game of college football."
Wyoming athletic director Tom Burman said in the same statement that he recognized Christensen's "sincere regret."
"The postgame actions and comments by coach Christensen do not represent Wyoming Cowboy football in the manner we expect, but I respect Dave for issuing his apology."