Cobblers boss Keith Curle was critical of referee Leigh Doughty and believes he unfairly leaned towards Bradford City during the second-half of Saturday's 2-1 defeat at Valley Parade.
Doughty, in his first season as an EFL referee, regularly had both sets of supporters bewildered and unhappy in equal measure during an inconsistent performance as Town left Yorkshire empty-handed after two late goals.
Curle was frustrated at full-time and felt Doughty had been influenced by a heated conversation with Bantams boss Gary Bowyer as the teams made their way off for half-time, at which point Town led 1-0
"It's going to sound critical but it's not meant personally, but their manager had a go at the referee at half-time and I think it affected him," claimed Curle.
"When we were leaving the pitch their manager had a go because he was disappointed with some of the decisions and I think that had an affect on the referee.
"Some of the decisions they got in the second-half, in my opinion, were not merited. It's not meant personally, but I think it's a professional learning curve for a young referee - do the right thing and don't try to show bias.
"He's a first-year referee, it's a big stadium, a big game and a big atmosphere and I didn't think he handled it well enough. I think he should have given what he saw and backed his judgement.
"Their manager will be happy because he knows he's had an affect on the referee."
Doughty did send off Bradford's Zeli Ismail for two bookable offences in stoppage-time but by that stage it was too late to alter the outcome.
Curle added: "As I was leaving the pitch I said it to him so I'm not talking out of turn - I think it's just an conversation and it's a valid observation.
"Hopefully the referee goes back and the referee's assessor goes back and they review the game.