Gareth Anscombe says Wales "had a lot of chances to fix" the mistake made by the TMO over his first-half "no-try" in their 12-6 Six Nations defeat by England at Twickenham.
Coach Warren Gatland called the decision a "terrible mistake" while England boss Eddie Jones said the TMOs must be respected.
Anscombe also felt Newman was wrong.
But he added: "It was still early on in the game and we had a lot of chances to fix it."
Newman ruled Anthony Watson had beaten the Welshman to the ball.
"The TMOs do not always get it right, which is frustrating but you can't do much about that," added Anscombe.
"We were confident once we saw the first replay and started jogging back, but whether there was a bit of a breakdown [between the match officials], there might have been.
"We trust the TMO, you've just got to back the individual to use the replays and communicate well with the touch judges and the ref, then hopefully they get the majority of them right."
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The Cardiff Blues utility back started at 15, filling in for foot infection victim Leigh Halfpenny, and moved to fly-half when Rhys Patchell came off and wing George North came on after the break.
"I felt some pressure of the ball on the ground, I thought that I got it down but the decision didn't go our way," said Anscombe.
"That was disappointing because it potentially would have changed the momentum".
England had established a 12-0 lead before the incident in the 23rd minute.
Referee Jerome Garces asked New Zealander Newman "try or no try" after Watson and Anscombe had dived on the loose ball in the England in-goal area.
After watching several replays, Newman replied "the first grounding was by England, therefore it is a scrum... no try."
A try would have made the score 12-5 with a conversion to come. Instead Wales managed two penalties as England produced a smothering defensive effort in the rest of the game to stop Wales scoring a try.
|What does law about grounding say?|
|A try is scored "by pressing down on the ball with a hand or hands, arm or arms, or the front of the player's body from waist to neck".|
|World Rugby law 21.1 b|