A rules controversy threatened to break out at The Open Championship after leader Lucas Herbert's caddie was spotted using what appeared to be a rangefinder in the second round, but the incident was deemed above board.
The LIV Golf star leads the tournament at eight under par after a sensational second round at Royal Birkdale. He made the turn in 28, and he missed a par putt at the last to break the record for the lowest score at a major championship
But he was thrust under the microscope after his looper, Nick Pugh, was spotted putting a visual aid to his eye. Rangefinders are permitted in LIV Golf events, but distance-calculating aids are strictly banned at The Open.
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A first offense would result in a two-shot penalty, and a second violation would result in disqualification.
Pugh's use of the device on the 14th hole was caught on camera by host broadcaster Sky Sports, and commentators feared Herbert could be punished.
Mirror Sports U.S. approached The R&A for clarification, and an official said the device was being used as a monocular without a battery. It does not have the capacity to calculate distances, meaning it is permitted for use.
Herbert started the day at level par, but he vaulted to the top of the leaderboard with six birdies on his front nine.
He picked up more shots on 11, 12, and 16, but he bogeyed the last to shoot a 62, tying the record for the lowest score in major history, which was set by Branden Grace on these links nine years ago.
Pugh made clear he had received approval from The R&A before using the rangefinder, telling reporters: "I'm sure you all know, we play on LIV Golf. On LIV Golf, we're allowed to use a rangefinder for distance measuring purposes.
"I obviously know that we can't do it here or at the U.S. Open recently, but there was another player at the U.S. Open whose caddie was giving the OK to use a rangefinder without the battery in.
"And I inquired very early on in the week with The R&A, one of the rules officials. I gave him a heads up, I said, 'Hey, this is what happened at the previous tournament. Would this be OK?"
"It obviously went to the power as it be, it went right to the very top, and I was given the green light. So I informed our playing partners on the first tee yesterday, I informed our walking referee, and I asked her for a second opinion. I said, 'Can you just make sure this is absolutely correct?' She came back on the second tee with a thumbs-up."