Mauricio Pochettino branded the Video Assistant Referee system a "nightmare" after Tottenham cruised into the FA Cup semi-finals with a 3-0 win at Swansea.
A double from the outstanding Christian Eriksen and an Erik Lamela strike secured Spurs a last-four tie at their temporary Wembley home next month.
But the victory was not without controversy as, with Spurs 1-0 ahead, Son Heung-min's 23rd-minute goal was ruled out for offside.
The incident was reviewed at length by VAR and, with the lines on the television proving inconclusive as to whether Son was offside or not, the original decision stood.