I fully agree with this, in the circumstances the player recognised that he moved the ball and then made a conscious effort, however negligible, to replace it marginally closer to the marker than the position it had moved to - as you say to fulfill the requirement that the ball was replaced in the correct place. I think if he had been conscious he had moved the ball he would have called a rules official and would have replaced the ball under supervision. I know it is a tiny amount and I know it made no difference to him holing the next putt but by the rules as I read them, unless he consciously made an effort to replace the ball back in it's original position before it had moved, he inadvertently broke the rule - as you say almost indistinguishably. I am really sorry to go on about this but my guess is Lucas Glover (who had just missed two very short putts on 17 and 18) was in a head scramble and didn't even realise he had done this - I would love to know if the USPGA have looked at the incident, as it is now being discussed on a number of golf forums, whether they have spoken to Glover and in fact ruled as you suggest that as it was such a tiny movement there was no conscious breaking of the rule.