Nebraska football coach Bill Callahan was reprimanded by the Big 12 conference on Thursday for his on-field behavior during last Saturday's loss against Oklahoma. The public disciplinary action by the conference came five days after Callahan got in a heated exchange with officials at the 10:58 mark of the fourth quarter. The Sooners' Kejuan Jones ran for a 17-yard touchdown, during which Callahan contended holding occurred. Callahan and referee Steve Usechek got in a heated exchange, and Callahan made a gesture by raising his right arm to his throat and making a slashing motion. Callahan acknowledged that he made a gesture out of frustration and meant no malice. "I understand coach Callahan's explanation of his gesture, however it resembled an action specifically prohibited by the NCAA football rule book (Rule 9-2-a-1-(a))," stated commissioner Kevin Weiberg. "This was out of character for coach Callahan. He has been very good to work with and his sideline demeanor had been exemplary. I have great respect for him and understand that he was acting on emotion. However, the Big 12 and its member institutions place tremendous emphasis on the conference's sportsmanship policy, and I believe his action in this situation constituted unsportsmanlike conduct and therefore warrants a public reprimand."