The intricate technicalities of the Decision Review System stumped some of cricket's top umpires on Friday, as they were forced to admit that an "honest error" had been made in an "extremely rare situation" during the second test between South Africa and Pakistan.
South African batsman Jacques Kallis was one of five wickets to fall to Pakistan spinner Saeed Ajmal on the second day of the match. But the officials involved in the decision later said through an ICC statement that they had failed to apply a key rule after the third umpire changed the mode of dismissal.
On-field umpire Steve Davis, who had already had two decisions overturned by the DRS, originally adjudged Kallis to have been caught by Azhar Ali at short leg.
Kallis immediately reviewed the call, and replays confirmed that he had not hit the ball. However, third umpire Billy Bowden then investigated the possibility that the batsman could be out lbw, and technology suggested that the ball would have hit the outside of leg stump.
Kallis was given out based on the "umpire's call" ruling, but the ICC statement later confirmed that this was in contravention to article 3.3 (f) of the DRS rulebook.
"The playing conditions state that when the third umpire observes that the batsman could be out by another mode of dismissal, the decision being reviewed using DRS should be as if the batsman had been originally given not out," the statement read. "Therefore, in this instance Kallis, as the point of impact was umpire's call, should not have been given out lbw."
The DRS has been a source of persistent controversy since its introduction by the ICC in 2008, and the powerful Board of Control for Cricket in India remains steadfastly against the initiative.
Nevertheless, the ICC insists the use of technology has improved the percentage of correct decisions being made at the top level of cricket.
Kallis himself has spoken out about the reliability of some of the technology involved - most notably when he questioned the accuracy of ball-tracking technology during a test series in New Zealand last year.
"I don't think there are any guys that are 100 percent sure that that thing is as accurate as they want to make it out to be," Kallis said. "They keep saying it but I'm not so sure, and I think 99 percent of cricketers will say that."