DeAngelo Williams’s touchdown (Katherine Frey/The Washington Post)

The NFL acknowledged Monday that officials erroneously awarded the Carolina Panthers a first-quarter touchdown during their win Sunday over the Washington Redskins when one of them inadvertently blew his whistle.

The play should have been ruled dead at the Redskins 17-yard line, according to a written statement by the league. The Panthers would have had the option of replaying that down or taking the play as it stood at the 17-yard line.

“By rule, Carolina should have been given a choice of putting the ball in play where [running back DeAngelo] Williams was ruled to have stepped out of bounds–1st-and-10 from the Washington 17 yard-line–or replaying the down–1st-and-10 from the Washington 30,” the league’s written statement said.

The NFL’s statement said “the Panthers were incorrectly awarded a touchdown following an inadvertent whistle.”

The inadvertent whistle—and the spot where the ball should have been placed afterward—was not subject to instant replay review under the NFL’s replay rules, according to the league’s statement.

The inadvertent whistle came on a 30-yard touchdown run by Williams.

Williams was near the sideline but never stepped out of bounds. Line judge Thomas Symonette blew his whistle inadvertently and signaled for the clock to stop, but Williams continued to the end zone. Redskins linebacker Perry Riley said after the game that he could have pushed Williams out of bounds if he hadn’t heard the whistle.

The officials spoke on the field but awarded Williams a touchdown. Referee Carl Cheffers said after the game that officials decided that Williams already was in the end zone when Symonette inadvertently blew his whistle.