Late in the first half of Thursday night’s NFL season opener, the Kansas City Chiefs had a defensive personnel problem on the field and needed a timeout. Defensive coordinator Steve Spagnuolo ran down the sideline and signaled for a timeout. It was granted.

There was a problem: only the head coach can call a timeout from the sidelines.

The timeout worked to the Chiefs’ advantage. With nine seconds left in the half and some time to regroup, the Chiefs forced an incomplete pass. The Baltimore Ravens settled for a field goal.

Although NBC’s replays did not show what Chiefs head coach Andy Reid was doing at the time, the network’s rules analyst Terry McAulay said on the broadcast that Spagnuolo’s timeout, if granted, should not have been granted.

“He can’t do that,” McAulay said. “The head coach has to come in. No one other than the head coach can call a timeout on the sidelines.”

NBC spokesman Mike Tirico said a referee “in the back corner” recognized Spagnuolo’s timeout and blew the whistle. Spagnuolo looked sheepish as he turned back to Reid after the timeout and appeared to apologize to the head coach for taking it upon himself to call a timeout. The referee walked right up to Spagnuolo and appeared to admonish him.

It worked. It’s possible that the Ravens lost a touchdown because of the timely timeout and a field goal was scored instead. That was a big reason why the Chiefs went into halftime with a 13-10 lead.

Reid may have called timeout, but the cameras were on Spagnuolo, as seen by Sam McDowell of the Kansas City Star.

Either way, it was a big moment in the first half. And one that will keep the Chiefs conspiracy theorists on their toes as the season begins.