The Kwiis failed to take their chances in an open game at the DW Stadium, but almost sneaked home in the final seconds.
In the end England ground out a 20-16 victory, which sealed the series 2-1.
Kenny-Dowall believed the Kiwis’ ball control and execution wasn’t up to Test match standard.
“It was a pretty sloppy game, the conditions weren’t great,” he said.
“We definitely didn’t capitalize on the opportunities that we had.
“We turned over far too much ball in good areas and that showed on the scoreboard I guess.
“I think it was a step backwards from the Second Test.
“We probably didn’t attack to the best of our ability last weekend. It’s something we’ve tried to work on and I think we probably didn’t execute well tonight either.
“We couldn’t get it right tonight again either so it’s disappointing.”
“We probably should have played a lot more footy than we did,” Kenny-Dowall said.
“We showed what we can do when we moved the ball around and we were probably one-dimensional for most part of that game.
“It probably showed in the way we did play towards the back end of the game. That’s the nature of the beast.
“When you’re chasing points and times not on your side, you want to throw the ball around and try and create an opportunity.
“I think we showed what we can do when we throw the ball around but it was too late, we didn’t have enough time. But we should have done that from the start.”
New Zealand were missing a host of key players for the series, including captain Simon Mannering, forward Jason Taumalolo and winger Manu Vatuvei, as well as 2014 Golden Boot winner Shaun Johnson, and 2011 NRL grand final winger Keiran Foran.
But Kenny-Dowall insisted that that was not an excuse for losing the series.
“The 17 you put out on the field is the 17 that are going to contest for the win and tonight we fell short,” the 27-year old said.
“It just wasn’t good enough.”