He had four consecutive bogeys before parring the 12th, despite the serenading of "Happy Birthday" from the crowds at every hole.
Mickelson said he knew the ruling was in his favour when he struck the ball, which could have left him a near impossible pitch shot. It looked like the ball was going to fly off the green when Mickelson hit the ball back towards the hole while it was still moving - which is illegal.
Strangely, the USGA deemed that Mickelson "played" the moving ball, rather than "moving or stopping" it, which could have brought disqualification into play.
"He didn't deflect it or stop it".
Mickelson's answer would suggest otherwise.
However, Mickelson, who eventually made a 10 on the 13th in a round of 81 which equalled his highest score in the US Open, said: "If someone is offended I apologise, but toughen up".
"Phil really did want to understand how the rule operates because he didn't want to - frankly, as he said to me: 'I don't want to play in this championship if I should have been disqualified, '" said Mike Davis, the USGA's chief executive.
Sanders thanks Rodman for being 'helpful' in North Korea
It is a great day. "I don't look at him as a dictator", Rodman insisted. "Obama didn't even give me the time of day", he said . White House officials have said that Rodman would play no official role in the diplomatic negotiations.
"I've wanted to do that many times".
The first two days of the tournament have seen near capacity crowds flood onto the course, about 26,000 on Thursday and more than 29,000 on Friday including spectators, vendor staff and volunteers.
However, U.S. Golf Association rules chief John Bodenhamer said Mickelson's breach did not reach such a level. I'm only messing.' I go, 'C'mon, that's the last thing I need!' So he was in the same spirit. Most related to Mickelson's actions, while others were simply stunned by the amateurish display. But Daly was always the combustible outlaw type, whereas Mickelson has a carefully cultivated image as one of the game's leading ambassadors.
Mickelson and playing partner Andrew Johnston were laughing about the incident as they walked off the green and Mickelson added: "How can you not laugh?" Then he kept on with his round and parred the most hard hole on the course, the 14th, still smiling and acknowledging fans.
'That's absolutely unbelievable, that's Phil basically giving up and saying, "No more",' David Fay, a former executive director of the United States Golf Association, said on American television.
The Shinnecock Hills course has a reputation for being a brutal test of golf in US Open conditions with slick greens and pins set in tough positions, allied to a baking sun and stiff breeze.
After the putt, commentator Curtis Strange may have summed it up best as Mickelson was walking off the green with a big smile on his face.
"I've never seen anything like it". "I think he just snapped at how bad his speed was on that putt".