The handling of the controversial decision review system call which spared Nathan Lyon has been labelled a "cluster f---" as it emerged Nigel Llong had not sat in the TV umpire's chair for seven months before the Adelaide Test.

New Zealand have sent a 'please explain' to the International Cricket Council over the controversial decision review system call, demanding to know how Llong arrived at the verdict which angered coach Mike Hesson and baffled many cricket followers. The Kiwis were confident they would have an appeal for a catch against Lyon overturned by DRS only for the original verdict to remain despite strong evidence suggesting the Australian had hit the ball.

"It was excellent, wasn't it?" Hesson replied when asked about his thoughts on DRS.

An insider familiar with the workings of TV referrals described the episode as a "cluster f---". It's understood officials were particularly embarrassed when Llong was sent the track for the wrong delivery during his deliberations.