Ian Taylor, the founder of the ball-tracking system, Virtual Eye, has called upon technicians and umpires to "fess up" and overrule DRS technology if they conclude that the system might have become unreliable because of unavailable data.
Taylor's call for umpires to use their discretionary powers to overrule technology followed a malfunction of the ball-tracking technology during the Hamilton Test between New Zealand and South Africa when data was collected from only two of the four cameras used to determine DRS decisions.
The failure by technicians and umpires to admit the shortcomings immediately will further embarrass the ICC, which continues to champion the system against resistance, particularly from India, and which has arranged for Cambridge University to run independent tests into its accuracy.
The latest debate broke out following the dismissal of the New Zealand batsman, Ross Taylor, on the second day of the second Test.
Taylor was given out lbw by umpire Billy Doctrove off the bowling of Dale Steyn late on the second day. The delivery was reverse-swinging and struck Taylor on the full. Ball-tracking predicted it would have hit middle and leg, which would have required a significant and unnatural angle change. In fact, after Virtual Eye was recalibrated, the ball would have only shaved leg stump. Doctrove's decision would still have been upheld by the television umpire, Aleem Dar, but the difference was still striking.
Ian Taylor, shaken by criticism of the system for the second successive Test, called a media conference in Hamilton at which he urged umpires to use the discretionary powers given to them to overrule DRS technology if they knew that complete data was not available or even if they felt strongly about a particular decision.
Virtual Eye's inventor said that the system had erred because after 6pm the ball-tracking cameras were not able to pick as much data up as they were earlier in the day when the light was brighter. In the case of Ross Taylor's dismissal, of the four cameras at the ground, one was facing direct sunlight, so it did not get the image, and another lost the ball, meaning that the data calculated for the predictive path was only obtained from two cameras.
In such a situation, Taylor simply wants his team to press the button that says "insufficient data available" and leave the umpire to take the final call on the dismissal. The implication was that they had not done this. "I said I would fess up if we got it wrong and we've got it wrong this time," Taylor said.
Ball-tracking technology came under the microscope during the first Test in Dunedin when both Jacques Kallis and Doug Bracewell said their respective camps questioned the legitimacy of the system. Kallis comment that "99% of cricketers" will probably agree that they don't believe ball-tracking is as accurate as the makers say it stung Taylor particularly hard.
He was close to pulling out of the series but was convinced to stay on after crisis talks with Sky Television, New Zealand Cricket and the ICC's general manager of cricket, Dave Richardson. "I really wish we had pulled it from the series then the players would have to argue with their boards whether they want to have it or not," Taylor said in Hamilton.
Meanwhile, Ross Taylor said he had no qualms about the system at all. "It's there for both teams and the umpire gave me out and the DRS gave me out as well," he said. When asked if it made a difference that Ian Taylor revealed that ball-tracking got it wrong, Taylor was unfussed.
"I'd rather you not have told me really," he said. "It's there. Umpires make the right decisions and umpires make a bad decision, I guess it's the same as the DRS."
Edited by David Hopps

Firdose Moonda is ESPNcricinfo's South Africa correspondent