The Open leader Lucas Herbert’s caddie was spotted using a rangefinder at Royal Birkdale.

A surge of both panic and intrigue briefly swept through The Open at Friday lunchtime when it seemed Lucas Herbert was in hot water at Royal Birkdale.

The Australian was on fire during his second round, tearing apart the Southport links by equalling both the lowest-ever Open front nine of 28 and the lowest ever round in a men’s major as he vaulted to the top of the famous yellow leaderboard. He finished one of the great Open rounds with an energy-sapping bogey, missing a four-footer for the lowest round in the tournament’s history, but still posted a majestic 62 to match the record.

On the 14th tee, though, Herbert’s caddie Nick Pugh was spotted using a rangefinder, but distance measuring devices are banned in competition at golf’s oldest major. Players, the rules stipulate, are prohibited from obtaining distance information by using an electronic distance-measuring device.

So on first glance, it looked like Herbert could be in big trouble, potentially at risk of being hit with a two-shot penalty to derail his good work. The devices are permitted for distance measuring at the PGA Championship by the PGA of America, but not at The Open.

TG asked Pugh after his round why he uses a rangefinder at Birkdale.

“On LIV Golf we’re allowed to use a rangefinder for distance-measuring purposes,” he explained. “I obviously know that we can’t do it here or at the US Open. But there was another player at the US Open that his caddie was given the OK to use a rangefinder without the battery in. 

“I enquired 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 in the previous tournament. Would this be OK?’

“It obviously went to the powers that 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?’ To which she came back on the second tee with a thumbs-up. 

“I’ll be honest with you guys- my eyesight isn’t great. The glasses aren’t just there to make me look cool! I sometimes struggle when the ball comes down. I mean, this guy hits it a long way. He hits it 380 yards yesterday with a 3-wood. And if he wants to know if the ball’s in the bunker or not, these old eyes don’t see it so well. So, I’ll generally use the rangefinder, which pretty clearly has no battery inside.”

A relief, then, for those backing Herbert to emulate 1991 champion Ian Baker-Finch as an Aussie winner here at Birkdale this weekend.