The New Zealand coach also believed the problem on Tuesday night was primarily in the goal attack position, with Brown (6/13) and Ameliaranne Wells (7/13), who was introduced for 18 minutes midway through the match, having very poor shooting returns.
While Mes (25/35) was also unsteady, Taumaunu said the rookie was able to get a lot of second-chance shots due to her strong rebounding ability.
While the same umpires will also be in charge of tomorrow's final test in Palmerston North, in which England will be chasing a historic series win on New Zealand soil, Taumaunu said Latu was still in consideration for the match.
"[The umpiring] was a concern and that was the reason behind [Latu] not getting a start, and we didn't put her on during the game as we felt Bailey was doing what we had asked of her and that was put up lots of shots and rebound strongly," she said.
"But that doesn't mean she won't be considered for the next game, because obviously Bailey got pulled for a few [offensive penalties] as well."
Difficulties with the Australian umpiring interpretations have been a perennial problem for Kiwi ANZ Championship franchisesin away games across the Tasman. But Latu tends to struggle more than most because of the way she uses her body to hold space.
"It's a little bit of an interpretation problem with the shooters, but we will keep working on it. We did get good clarity from the umpires when they came into training about what they would be looking for," said Taumaunu.
The goal shoot position presents a major selection headache for the NZ coaching staff.
While Latu's accuracy is impressive, typically posting figures in the 90s, her volume is a major concern, indicating she is not getting her hands on the ball in shooting positions often enough. In the two full games both Latu and Mes have played this season, Latu averaged 26.5 shots at goal, while Mes averaged 34 attempts per game.
It was hoped with more game time Mes would get better at sinking shots under pressure, but after two shooting efforts in the 60s, you have to wonder how much longer Taumaunu and co can afford to persevere with her.
Silver Ferns' 2014 disasters
Ocker shocker
After injuries ripped through their shooting line-up, the Ferns suffered a humiliating 18-goal defeat to Australia in the Commonwealth Games final in August.
More shockers
They went on to suffer several more heavy losses to the Diamonds in the Constellation Cup this month, losing the series 4-0. They also lost their courageous captain Casey Kopua in game three to a serious knee injury.
... and even more
The Ferns hoped to restore some confidence in the camp after a demoralising season with some strong performances against England in their final hit-outs of the year. Instead they opened the series on Tuesday night with a 42-38 loss.