Following the controversy surrounding Lexi Thompson's four-shot penalty during the ANA Inspiration in April, golf's governing bodies announced a new two-part rules decision to allow officials more flexibility in certain situations.
A joint statement from the R&A and USGA said players "should not be held to the degree of precision that can sometimes be provided by video technology'' on matters of location such as ''determining the nearest point of relief or replacing a lifted ball''.
It added: ''So long as the player does what can reasonably be expected under the circumstances to make an accurate determination, the player's reasonable judgement will be accepted, even if later shown to be wrong by the use of video evidence.''
Rahm appeared to incorrectly replace his ball on the sixth green after moving it out of the way of playing partner Daniel Im, but was not penalised after speaking to the tournament's chief referee Andy McFee on the 13th.
"One of the points in the new decision is that the outcome depends a lot on what the player says and his explanation of the events," McFee said. "He said I knew I marked it to the side and then I was trying to make an effort to put it back to the side. He's definitely made the effort.
"We're talking about the difference between the ball being lifted at 10 o'clock on the ball mark and put back at 11 o'clock, which is not a problem.
"Has he got it back in exactly the right place? No. But has he got it back in a place that's good enough, yes.
"As a self-governing sport this game is all about players making reasonable judgements and the game has come to the conclusion that it's not right that that principle is second guessed every time somebody gets it a millimetre wrong.
"The whole purpose of that decision is to give a player the opportunity to walk away with no penalty when he's perceived to be doing the right thing."
Rahm was keen to address the issue in his post-round press conference, adding: "I knowingly put my marker on the side of my ball. I know it's a little suspicious sometimes but I knowingly did it.
"I moved my marker so it was not in the way of Daniel's and put it back, and when I replaced my ball I thought it was in the same exact spot.
"Then Andy came and told me on 13 that they had had a couple of complaints that I had put the ball in a different spot. I told him, listen, if it's a penalty stroke, let me know now, I'll accept it.
"He told me there's been a change in the rules. There's some margins left on the rule now and it was left to interpretation."
Thompson was told during her final round of the ANA Inspiration that footage of the previous day's play showed she had incorrectly replaced a marked ball. The American was penalised two shots for the offence and a further two for signing an incorrect scorecard. She went on to lose in a play-off.
"I think the margin in the Lexi Thompson (case) would be slightly different to this one," McFee added. "This one is not quite that stark.
"And also the big difference is that in this case, you've got an intervening act. You've got the player moving the ball marker off to the side and then moving it back again. That by itself means that the ball is probably not going to go back in exactly the right place."
