And he admitted that a lot of the problems were of their own making as Wolves ruthlessly punished the visitors' errors.
McNamara said the lapses were born out of a lack of focus and said the Bulls' effort were unacceptable after they had turned round 8-6 in front.
"It was nip and tuck there but unfortunately for us we just imploded with the number of errors we kept making," he said.
"I'll accept anyone who makes an error, it's part of the game. It is the lack of concentration and application which really hurts and there was some of that in the game for us and we won't tolerate it.
"We put ourselves under pressure and it became too much in that last 20 minutes.
"In the second half we repeatedly made errors coming out of our own end and against a side of Warrington's quality you are not going to get away with it.
"In the first half both sides were off the mark in terms of skill levels and whichever side picked it up in the second half would go on to win the game."
Tries from Andy Lynch and Paul Sykes gave the Bulls their slender half-time advantage with Richie Myler crossing for Warrington on his return from injury.
But an awesome second-half display that included two tries apiece for Ryan Atkins and Matt King as well as one from Michael Monaghan ensured a comprehensive win for the Wolves.
Myler's return to the side meant Monaghan reverted to hooker and Mickey Higham dropped to the bench.
Winger Rikki Sheriffe was back in the Bradford side after recovering from the hamstring injury that forced him to miss the previous week's win over Wigan.
The only other change saw Glenn Hall start in place of Jamie Langley in the forwards.
Matt Orford missed a chance to give the visitors the lead in the 11th minute with his penalty attempt coming back off an upright and Warrington recovering the ball in the resulting scramble.
Both sides struggled to gain momentum with a number of handling errors costing them.
Nick Scruton went close to breaking the deadlock in the opening 20 minutes but he was held up after a surging run to the line.
The visitors then opened the scoring after the midway point of the first half.
Warrington full-back Chris Riley dropped a towering high ball, leading to a sustained period of pressure for the Bulls which ended with Lynch crashing over the line.
After a video referral the try was given but Orford missed the conversion.
Warrington hit back with Myler racing over from more than 30 metres following a searing break in midfield from Higham and Chris Bridge added the goal.
Bradford reclaimed the lead three minutes before the break with Orford creating the space to send Sykes over the line but the centre could not convert his try.
Warrington went on the attack immediately after half-time and they gained a rapid reward when Atkins went over in the corner to put the hosts back in the lead.
After Higham was held up over the line a couple of plays earlier, Warrington fizzed the ball across the backline and King drew two defenders before sending Atkins over. Bridge's conversion attempt fell short.
Warrington gained some breathing space on the scoreboard minutes later when King went flying over in the same corner after some good work from Louis Anderson.
There was even more joy down the left flank for Warrington straight from the kick-off.
Again King caused havoc for the Bulls' defence and, once behind the defence, he delayed his pass just enough to give Atkins time to race to the line. Bridge added his third conversion.
Monaghan got in on the act as he crossed with 12 minutes remaining without a Bulls defender laying a hand on the hooker, Bridge converting again.
Monaghan then added a drop-goal to underline the Wolves' superiority and another late, converted try from King capped a resounding win.
Warrington coach Tony Smith praised his players' second-half performance after their blitz had blown away the Bulls to maintain the pressure on Wigan Warriors at the top of the Super League.
The pace and finishing power of Atkins was especially impressive given he was reportedly woken at 6.30am on the day of the game for a random drugs test.
Smith insisted he would take the issue up with the appropriate people at another stage, but did not want to dwell on the subject following a fifth win in six games.
"It was an ugly first half again," Smith said. "We are making a bit of a habit of it but fortunately we are making a habit of getting it in order for the second half.
"I think that is the third team we have shut out in the second half, which is encouraging. From a team point of view it was one good half and one half that we will look at and learn from."
As well as praising Atkins and King for their tries, Smith emphasised the impact of forward Adrian Morley.
"Not many props can do 80 minutes but he earned 80 minutes, I did not do him any favours tonight," Smith said.
"He earned the right to stay on the field. How he got overlooked for the man-of-the-match award I will never know."
Warrington Wolves: Riley, Hicks, Bridge, Atkins, King, Grix, Myler, Morley, Monaghan, Carvell, L. Anderson, Westwood, Harrison. Substitutes: Wood, Higham, Solomona, V. Anderson.
Bradford Bulls: Halley, Sheriffe, Sykes, Nero, Reardon, Kearney, Orford, Scruton, L'Estrange, Lynch, Whitehead, Hall, Menzies. Substitutes: Godwin, Kopczak, Worrincy, Donaldson.
Referee: S Ganson (St Helens).