I think capacity is only 11500??? IDK, there were clearly some empty seats, mostly in the lower sections. But attendance was fine and the crowd was loud, so I have no complaints.
"And Saturday’s game against West Virginia was in the midst of the largest estimated fan attendance this season. Oklahoma provided another down-to-the-wire thriller to its audience of 10,346. Saturday's packed arena etched out the previous season-high attendance count of 10,116 against then-No. 11 Iowa State."