England had been aiming for a 3-0 series whitewash, but conceded six tries to an impressive Kiwi side.
“We gave them a bit too much cheap ball at times and they played better,” Myler reflected.
“That’s the best they’ve played this series and we didn’t put our best foot forward.”
England had three touchdowns ruled out by video referee Phil Bentham – the first after man in the middle Gerard Sutton had indicated a try.
Myler added: “There were a few things that were close calls, it is fine-line stuff and if it goes the other way then maybe it’s different.
“But we weren’t at our best and they certainly were.
“Credit to them, they did well.”
England’s wins in the opening two Tests secured the Baskerville Shield and Myler admitted they would have settled, before the series started, for a 2-1 triumph.
“That’s what we set out to do, to win the series and that’s what we’ve done,” he said.
“This group’s depleted of a few numbers and we’ve turned around and come up with a result which we are very proud of.
“It’s a little bit of a downer because we didn’t finish the job off today, but there’s a lot to build from.
“Once we get a few more players in the squad we can keep building.
“We are definitely making progress and we can look forward now to future events.”
Yesterday was Myler’s first appearance of the series and he added: “It was disappointing we got beat, it was not the result we wanted, but a good feeling to get out there and get a run.”
England coach Wayne Bennett insisted yesterday’s result did not take the gloss off the series success.
He said: “I wasn’t happy with the performance, but I accepted what happened out there and I understand it probably better than most so I can move on the team from there.
“You never see a scoreline like that coming, but it happens. It was a combination of things, injuries and we didn’t have a lot of luck.”