The NFL acknowledged Friday that an errant whistle cost the Cleveland Browns a fumble recovery in their 45-42 overtime loss to the Oakland Raiders on Sunday.

The play, one of several controversial calls in the game, occurred with 6 minutes, 39 seconds remaining in regulation. Raiders quarterback Derek Carr lost control of the ball after Browns pass-rushers Myles Garrett and Genard Avery hit him at the Oakland 38-yard line. Garrett recovered and began a return toward the end zone.

But referee Walt Anderson stepped in, ruling that a whistle had blown before the fumble because Carr's forward progress stopped. Anderson ruled the play a sack, and the Raiders punted on fourth down.

In a weekly video review released on Twitter, NFL senior vice president of officiating Al Riveron said: "We rule the passer stopped for forward progress and we kill the play. This is not forward progress. Obviously, this is a fumble. We should not have blown the whistle."

By NFL rule, Anderson's call was not reviewable.

The Browns were also on the short end of another controversial ruling late in the game: Riveron's decision to reverse a key first-down measurement with 1:38 left in regulation.

Riveron did not mention it on Friday's video, but the league had earlier supported the ruling by saying Riveron determined Browns running back Carlos Hyde should have been marked one yard short of the first down. According to the league, Riveron pieced together the ruling by looking at evidence from two different views of the play.