Late in the first half in 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 signaling for a timeout. It was granted.

There was one problem: Only the head coach can call a timeout from the sideline.

The timeout helped the Chiefs. With nine seconds left in the half and some time to regroup, the Chiefs forced an incompletion. The Baltimore Ravens settled for a field goal.

While all of NBC’s replays didn’t show what Chiefs head coach Andy Reid was doing at that moment, the network’s rules analyst Terry McAulay said on the broadcast that if Spagnuolo’s timeout was granted, it shouldn’t have been.

“He can’t do that,” McAulay said. “It has to be the head coach who comes down. Nobody else can call a timeout on the sideline except the head coach.”

NBC announcer Mike Tirico said that an official “in the back corner” recognized Spagnuolo’s timeout and whistled for it. Spagnuolo had a sheepish look when he turned back to Reid after the timeout and appeared to be apologizing to the head coach for taking it upon himself to call a timeout. The referee came right to Spagnuolo and appeared to admonish him.

It worked. It’s possible the timely timeout from the defensive coordinator cost the Ravens a touchdown, and they got a field goal instead. That was a big reason the Chiefs went into halftime with a 13-10 lead.