COOPERSTOWN, N.Y. -- Joe Torre said here on Thursday that the disputed home run call in the Yankees-Royals game on Wednesday night in Kansas City was due to the umpire's misunderstanding of the ground rules at Kauffman Stadium.

Royals designated hitter Billy Butler was wrongly credited with a third-inning solo home run, even though the shot was reviewed via instant replay, said Torre, Major League Baseball's executive vice president of baseball operations and a former Yankees manager.

The ball struck the top of the left-field wall, a section of railing that is still in play at the Kansas City ballpark, and bounced back on to the field. Even after the review, crew chief Dana DeMuth signaled that it was a homer. The call was decisive as the Yanks lost, 5-4, leaving the bases loaded in the ninth inning when Jorge Posada struck out looking to end the game.

"There really was a misunderstanding about what the ground rule represented," Torre said as two days of Owners' Meetings ended at the Otesaga Resort Hotel. "The cushion and the little screen and railing are in the ballpark. I talked to Dana DeMuth, and obviously last night from what went on, he was very sure that that ball was a home run because it hit that back fence, which he thought was out of the park."

Despite the obvious misunderstanding of the ground rules, Torre said the issue was moot and the final score stands. Yankees manager Joe Girardi didn't protest the game, which he must do prior to the next pitch after the incident, Torre added. Girardi second-guessed himself for not doing so.

"He said, 'It's clearly a home run,'" Girardi told reporters after the game about DeMuth. "Maybe I erred. I believed the umpire."

DeMuth declined to comment after the game, because he was being advised about the ground rules and was still trying to digest the mistake. Torre said DeMuth would be available to the media on Friday through MLB or before the game at Angel Stadium, where he is working on Friday night.

Royals manager Ned Yost didn't have much to say on the subject.

"I don't have any reaction to it," he said. "Joe Torre said what he said."

As far as Torre's ruling, Butler was just as quiet as his manager.

"I've got no comment on it," Butler said. "It's a big part of the game, we won by one run."

Torre said that Steve Palermo, an umpires supervisor who was in attendance at Kauffman Stadium, took the crew out to the left-field fence well after the game and pointed out the discrepancy between the ground rule and what was called.

"He had to take them out there and explain what actually is a home run," said Torre, who was hired for his current job this past March after retiring as manager of the Dodgers last year. "The universal ground rule is 'out of the ballpark.' It has to disappear, basically. Dana feels very badly about it. He's usually very astute and usually knows the ground rules."

Torre added that though the Yankees didn't officially protest the game, he interjected himself into the situation because, "I knew there was going to be a lot of questions."

The Yankees lead the Red Sox by a half-game in the American League East, and the loss could have serious playoff implications. Both teams seem destined to go to the postseason, but which one wins the division and which one is the Wild Card will determine home-field advantage and first-round matchups.

"This was very unusual, and I certainly have empathy with Joe," Torre said about Girardi, the man who replaced him as Yankees manager after the 2007 season. "This umpire has worked three years in this ballpark [since it was refurbished] and was under the assumption that that was a home run because the fence is behind the padding and out of the ballpark. This was the basic misunderstanding. I don't think it was as much a blatant miscall as it was a misunderstood ground rule."