The ICC has stated they 'do not comment' on decisions made by umpires.
Given the history of proven match-fixing in the UK, plus some of the other decisions in that game (Nicholls, Taylor, etc) I will therefore choose my own conclusions about this mysteriously poor call that kept the home side of one the ICC's big three in the hunt at their own World Cup.
A bit cynical buts its hard not to look at that. UK is the home of cricket. Just as the quinitessential All Blacks are the home of rugby. UK cricket is old and steeped in tradition. The old fogie members in the Lords big room, and outside the door, clap as players move in and out. That is SOLELY tradition based. Its the Freemasons of cricket. UK has never won the World Cup. That cant keep happening
Cricket has been corrupt. Including NZ involvement. The much loved and respected Hanse Cronje who captained Soutb Africa took his own life when he was found out. UK cricket, the big one of the big three is NOT the Wimbledon of cricket in terms of class and vales
It's a bit discouraging to see conversations head in this direction. the C word is a big call in a situation like this one. It's much more likely a genuine mistake and failure to follow escalation or a system type issue than what you are suggesting.
It's pretty clear it was an incorrect call as confirmed by a number of well respected former referees, but to suggest it was definitively a game result changer is taking it too far.
It's disappointing ICC passed the buck, but if that's consistent with their other invitiations to comment of other refereeing decisions, then no-one can really complain.