The golfing world has seen its fair share of controversy in recent times when it comes to moving balls.First it was Phil Mickelson intentionally hitting a moving ball to prevent it from rolling off the green at last weekend's US Open - and now fellow American Zach Johnson has fallen foul of the rules at the Travelers Championship in Connecticut on Friday.Johnson (42) faced a dilemma after his putt for a birdie stopped on the lip of the par-four third during his second round. Upon seeing where his ball had landed, Johnson hesitated to play his next shot as he was unsure whether the ball was still moving.Ultimately, the ball would drop into the hole on its own - just as Johnson was about to knock it in.Frustratingly for Johnson, though, he was penalised an extra stroke as the ball had taken more than 10 seconds to drop in.Like Mickelson, Johnson did receive a penalty - albeit for far less of an infringement - but admitted that he understood the reasons behind the ruling.

Speaking to Sky Sports, Johnson explained the circumstances which led to his "ghost" shot.

"When I got to the ball I thought it was moving a little bit, but it was not - it was at rest...Within ten seconds if that ball falls in, it would count," said Johnson, who then went to confirm that he had no issue with the decision following discussions with tournament officials.

"By the time I went to tap it in it was like 15-plus seconds, so regardless of if it were to hit it, or if it falls in, then it doesn't count. 

"They were very clear. Technically they were right...The rule is specifically if the ball is on the lip of the hole - and I understand that."

Few would have been surprised had Johnson taken the news of his penalty in a far worse manner.

After all, the penalty stroke he picked up actually cost him a share of the tournament lead. His reaction should be contrasted with that of Phil Mickelson, who took four days to apologise for his actions at the US Open - and even then did so via a text message to reporters.

Disappointment, anger and frustration are very much a part of professional golf and Zach Johnson deserves credit for the way in which he carried himself after his unfortunate setback.