Anyway, the USGA and the R&A have issued a new Decision 18/4. As of 2014, if a ball's movement is "not reasonably discernible" to the naked eye, no violation will be called at the time or later, regardless of whether video evidence exists otherwise.
Just in case you need more detail to understand the new interpretation of the rule, here's the statement the ruling bodies released to explain it:
In recent years, the rapid development of video technology, such as HDTV, digital recording and on-line visual media, has brought a new level of scrutiny to Rules issues arising in elite golf tournaments. This has led to an increasing number of inquiries to officials from television viewers and others about whether a breach of the Rules has occurred, sometimes resulting in breaches of the Rules being identified (and penalties being applied) after the incident itself occurred. Occasionally, the identification of the breach has been after the player has returned his or her score card, which has therefore resulted in disqualification under Rule 6-6d. These developments have generated considerable discussion concerning whether, how and when such video evidence should be used.
The Rules of Golf Committees of the USGA and The R&A have been reviewing the operation of the Rules in the light of these continuing technological developments in order to determine whether any changes to the Rules are appropriate. In April 2011, the USGA and The R&A adopted Decision 33-7/4.5, which authorizes Committees to waive the disqualification penalty for a breach of Rule 6-6d in narrow circumstances in which the player could not reasonably have been aware of a breach of the Rules that later was identified only through video evidence.
Since adopting Decision 33-7/4.5, the USGA and The R&A have continued to review the impact of video technology on the game. With input and assistance from representatives of the professional tours who serve as consulting members of the Rules of Golf Committees, the USGA and The R&A are now introducing a further modification of the Rules, with effect from January 1, 2014, to address the use of video technology in determining whether a ball at rest has “moved” within the meaning of the Rules. New Decision 18/4 will provide that, where enhanced technological evidence shows that a ball has left its position and come to rest in another location, the ball will not be deemed to have moved if that movement was not reasonably discernible to the naked eye at the time. The Decision ensures that a player is not penalized under Rule 18-2 in circumstances where the fact that the ball had changed location could not reasonably have been seen without the use of enhanced technology.
Beyond these Decisions, as part of the 2016 Rules review, the Rules of Golf Committees will be discussing other issues concerning the possible effect of video technology on the application of the Rules to the playing of the game, such as the necessary degree of precision in marking, lifting and replacing a ball, the estimation of a reference point for taking relief, and the overall question of the appropriate penalty for returning an incorrect score card where the player was unaware that a penalty had been incurred. As is true of the rules in many other televised sports, adapting to developments in technology and video evidence is an important ongoing topic in making and applying the Rules of Golf.
In pursuing this continuing review, the USGA and The R&A will be guided by their longstanding position that a Committee should consider all evidence, regardless of the source, that may be relevant in determining the facts to which the Rules must be applied. As reflected in the interpretations contained in the Decisions, for questions of fact, the resolution of doubt must be made in the light of all relevant circumstances and be based on the weight of the evidence. To reach a correct ruling, all evidence from witnesses concerning a possible breach of the Rules should be considered, whether those witnesses are participants in the competition, non-participants such as spectators, or persons who have reviewed television footage and the like. Additionally, the Decisions provide that a Committee may make or revise a ruling at a later time if further information becomes available before the competition has closed.
In many other sports, there are good and understandable reasons for imposing a strict time limit on the review and correction of rules decisions. In golf, however, even at the elite level, players often apply the Rules to themselves without the assistance of a referee and, in stroke play, are responsible for the correctness of the score recorded for each hole. Moreover, competitions are often played over more than one day and, in stroke play, the outcome typically is based on total score, making it possible to correct errors significantly after the fact and, indeed, at any time before the competition is closed by virtue of the result being officially announced. For these reasons, disregarding relevant evidence of a breach of the Rules, obtained before the competition has ended, could lead to uncertainty and to unhealthy debate and disagreement about the fairness of a result that was influenced by an incorrect set of facts and failure to apply the Rules properly. If a player has breached a Rule, but this is not discovered until a later time, whether through video evidence or otherwise, such evidence must be considered so that the correct ruling can be applied and the player’s score can be recorded accurately.
In their ongoing review of the use of video and other enhanced technology, the USGA and The R&A will continue to be guided by the view that, regardless of the timing or the type of evidence used, the integrity of the game is best served by getting the ruling right.As long-winded as they may be, I dare say I agree with the decision.
Among many other books, Dave Donelson is the author of Weird Golf: 18 tales of fantastic, horrific, scientifically impossible, and morally reprehensible golf