Rory McIlroy’s drop Sunday at the U.S. Open was incorrect, the USGA says.

In speaking to Sports Illustrated, Thomas Pagel, the USGA’s chief governance officer, explained that McIlroy, under guidance from a rules official, measured his point of relief from an embedded lie in the fescue above a greenside bunker from the wrong spot on the par-5 14^th hole at Los Angeles Country Club.

“The nearest point of relief was mis-identified; it should have been directly behind the ball,” Pagel told SI. “If there’s no area immediately behind the ball, you go to nearest point in the general area. But if you look at where the ball was embedded, there was a grassy area below and that should have been the starting point.”

McIlroy was in contention when his wedge shot came up short and plugged into the thick rough. After a brief search, playing competitor Scottie Scheffler discovered the ball, at which point rules official Courtney Myrhum, a veteran of over 60 USGA championships, was brought in to help McIlroy drop. McIlroy then removed his ball, marked the spot with a tee and then took his drop, as the rule states, one club length no closer to the hole from the spot to be deemed the general area of the embedded spot.

While McIlroy ended up taking improper relief, Pagel insisted that McIlroy did nothing wrong. He also said that the difference in McIlroy’s drop and the correct drop was about 18 inches and that ultimately, McIlroy didn’t gain any advantage as either way he was dropping on the same shelf right of the green.

McIlroy would fail to get up and down to save par, and he eventually went on to finish runner-up, one shot back of champion Wyndham Clark.

“His ball was 100% embedded,” Pagel added. “And an embedded ball not in sand is entitled to relief. Now Rory did everything at the discretion of the referee. In her discretion, her judgment was that the reference point for relief was to the side of the ball. And from a ruling standpoint, that’s the end of the story.”