Dustin Johnson claimed his first major championship win at Oakmont on Sunday when he roared home at the 2016 US Open but it's the rules controversy which shadowed the back nine that will grab a lot of headlines.

On the fifth green Johnson was faced with a six-foot putt. He took a number of practice strokes before going to address the ball but, crucially, didn’t ground his putter.

Before he was able to to lay the putter on the ground his ball oscilated ever so slightly backwards.

Johnson immediately stepped away from the ball and told playing partner Lee Westwood what had happened. He then called over a rules official and, along with Westwood, told him that the ball had moved.

It was clarified that Johnson had not grounded the putter and the situation, seemingly, was resolved.

A similar occurence had happened to Shane Lowry in the second round but the Offaly man was penalised a shot as he had grounded his putter.

After looking back on the video footage numerous times it seems clear that Johnson had not grounded his club or touched the ball with it.

However, it didn’t end there.

While waiting on the 12th tee box Johnson was approached by a rules official.

The USGA representative explained to him that they had reviewed the footage and they felt that Johnson himself needed to look at it as he may have caused the ball to move.

Instead of implementing a short stoppage in play to do that there and then they instead decided that the footage would not be reviewed until after the round.

That meant that Johnson had to play his final seven holes with a potential one stroke penalty coming after the round.

The USGA confirmed that the rest of the field had also been informed of the potential penalty.

In the end it didn’t matter as Johnson closed out superbly to win by four shots.

Well, it was four shots until the video footage was reviewed once he’d putted out on the 18th green.

The result of that review was that Johnson had caused the ball to move and was therefore penalised one shot. His winning score was revised to four under par.

But Johnson was the winner so it didn’t matter. But the fact is that it did matter.

It mattered because what was a potentially very simple situation to resolve was instead dragged out to become a controversy that will hang over this championship for the coming days and weeks.

Speaking after the completion of play, Jeff Hall of the USGA offered the rules officials’ take on the incident.

“The ball moved. When we evaluated the video with Dustin we were satisfied that his actions had caused the ball to move and he was penalised one stroke.

“I was out on the golf course shadowing the last few groups when a member of our staff told me that I should come in and have a look at the video. A few different factors needed to be evaluated in this case – the proximity of the player to the ball, the proximity of his actions to the ball, plus other considerations.

“We wanted to talk to Dustin about it and by the time we were able to do that it was the 12th tee. We had a conversation with Dustin to let him know that we were concerned about his actions near the golf ball and that there might very well be a penalty, but we wanted him to know and we wanted to ask him the question: ‘Was there something else that could have caused the ball to move, Dustin?’

“As we started into that discussion it was very apparent that it was going to be a very protracted discussion so we said I think probably the best thing to do is to let you have a look at the video so that he could see what we saw.”

But it would it not have been possible to take Johnson into the TV compound (located beside the 13th tee box) and show him the video then?

“We opted not to do that. But we did inform the field before Dustin finished the last hole.”

Criticism of the USGA was in abundance on social media with the likes of Rory McIlroy and Jordan Spieth reacting to the controversy.

When asked about that, Hall said: “I think every situation is unique. You’ve got to review the facts and do the best you can. It’s a tough situation, we did the best that we could and we feel pretty comfortable with the process that we had in place.”

In a way the USGA were lucky that Johnson went and won comfortably. Had he finished in a tie and was then penalised one shot the fiasco would have got a whole lot bigger.