Noh, playing at Ridgewood Country Club in the second round of the FedEx Cup playoff event, hit a wayward tee shot on the 11th hole that came to rest on the putting surface of the third hole.
After waiting for the group to putt out on the green, Noh played his second shot, taking a big divot out of the green. He later learned that is not allowed.
The mistake meant a 2-stroke penalty. Under Rule 25-3, a player is required to take relief at the nearest point, no closer to the hole.
"It's the most unusual ruling I remember, ever," said Slugger White, the PGA Tour's vice president of rules and competition. "I asked my staff, and no one had ever seen it. And that's a lot of years out here."
Noh and his caddie, David Brooker, said they were unaware of the rule and never sought a rules official to clarify.
Graeme McDowell, who, along with George McNeill, played with Noh, said he, too, did not know it was a penalty.
"I feel badly for him," McDowell said. "He played very nicely. I didn't know it, either."
White said that one of his rules officials was alerted to the problem by a marshal who wondered whether hitting from another green was allowed. That official, Brad Fabel, then got to Noh, who was informed of the 2-stroke penalty, changing his bogey-5 to a 7.
"The rule is very clear," White says. "There is no doubt about it. It says you must take relief."
The ball should have been dropped one club length from the green at the nearest point where it came to rest, no closer to the hole.
Noh, 23, won the Zurich Classic of New Orleans earlier this year and is 42nd in the FedEx Cup standings. With the penalty, his score was a 1-over-par 72, and he completed 36 holes at 2-under-par 140.