The much talked about the Decision Review System (DRS) came under more scrutiny during the first Test match between South Africa and Australia at Gabba in Brisbane.
Australia opener Ed Cowan survived a debatable call and South African veteran Jacques Kallis was forced to defend his role in the dismissal of team-mate Hashim Amla .
The third day began controversially for the Proteas when Amla (104) defied temptations to call on the DRS after being trapped in front by Peter Siddle just five overs after posting his 17th Test century.
Amla and Kallis discussed briefly mid-pitch before the right-hander walked back to the pavilion despite South Africa having two challenges up their sleeve.
However, the decision backfired badly, with replays showing the Siddle delivery struck Amla high on the pad and would have sailed over the stumps.
The Proteas then suffered another setback just before stumps when Cowan (49 not out) gloved behind off Morne Morkel, only to be given a let off when a review showed the South African quick had no-balled by millimeters.
Kallis said he rued the decision not to review the Amla leg before wicket decision.
"It was a chat that we had, I said to him the height may have been an issue there and he felt no it wasn''t going to go over because the umpire gave it out and he felt it wasn't (bouncing) high enough," News.com.au quoted Kallis, as saying.
"It was a tough one to call, maybe I could have said to him just refer it, because we do have two, so maybe I can take a bit of blame for that," he added.
"It was a discussion we had, but as a batter sometimes you get a feel for it and he felt it wasn''t too high. He thought it was probably clipping the stumps," he said.