Just replayed it back a couple of times, the second Hanley plays the ball there is no marker Farrel is on the left Marshall on the right. When Newman does his nutmeg dive Marshalls left leg comes across to block the move but it was too late.
At normal speed it looks an obvious no try, because it went up to a video ref he spotted it in slow mo. Ii also looks as though Newman didn't touch Hanleys legs to question an obstruction.
If that was a non televised game it would 99 times out of 100 a NO TRY.