That cloud loomed because of a season-ending injury to star slot receiver Ryan Broyles.
Late in the third quarter, after Broyles snagged a crossing pattern and carried an A&M defender down to the 22-yard line for 30 yards, he was wrestled down awkwardly to the ground and had to be helped off the field.
He was taken to the trainer's table, where the sight told it all.
A trainer whispered something in Broyles' ear and he ripped his helmet off and starting crying.
What he was crying about and OU fans' biggest fear, head coach Bob Stoops confirmed after the game.
"Sad to report Ryan Broyles tore his anterior cruciate ligament," Stoops said in his post-game press conference. "He will be out for the year. We are all disappointed for Ryan. He is a special, special player that everyone has talked about all year, and for that to happen, it's just deflating for him and for all of us."
Immediate teammates' reactions said the same.
"It is a bad deal," said quarterback Landry Jones, the man on the team who perhaps knows him the best. "There is nothing we can do about it. It is just one of those things that happens. Just praise God that Ryan is not defined on who he is on the football field. Ryan is a man of God first. He will definitely have that to lean on and have that peace about him. Obviously, it is just not something you want for someone like that."
"Losing a team captain always hurts, but this just means that we have to step up our game as receivers and show everyone what we're made of," said wide receiver Jaz Reynolds.
"First thing I can do is just pray for him," said defensive back Javon Harris. "Knowing he's an impact player on our team, that just means everyone else has to step up."
Co-offensive coordinator Josh Heupel expressed the same sentiments about his veteran leader.
"First of all, I feel for Ryan," Heupel said. "All he has put in and the effort and everything he has done since he has been here. The man he is. We will need him to bring those characteristics to us even with the injury. At the same time when someone steps down or someone goes down the next guy steps up and can play at a high level.
They can't take someone's role, but they can become a playmaker, take advantage of the opportunity."
Broyles leaves behind a storied career of numerous records, including the all-time receptions mark he set a few weeks back against Kansas and others.
Against the Aggies, he moved into second all-time on the FBS career receiving yards list with 4,586, surpassing Wyoming's Marcus Harris from 1993-96, and he was within striking distance of Nevada's Trevor Insley, who racked up 5,005 career yards in the late 90s.
He led the team with his 1,157 yards and 10 touchdowns on 83 receptions.
Now, it'll be time for guys like Kenny Stills (610 receiving yards) and Reynolds (578 receiving yards) to emerge as the true leaders on this receiving corps the rest of the season, and others, such as DeJuan Miller and Trey Franks have to elevate their games as well, as Heupel alluded to.
"Someone else has to come in and step up," Jones said. "Trey came in and played good. We are going to have to have him step up in a big way."