Guillem Bauza gave Northampton the lead after 39 minutes but Aaron Webster hit back for the Brewers just four minutes later to leave Johnson still waiting for his first win.
He said: "I wasn't really pleased with a point because we came here trying to get the win but in the end a draw was probably the fairest result.
"Both teams were a little bit nervous and showed a lack of confidence and quality in the final third.
"We had lots of set plays but we never quite got the ball on the button. Maybe that was down to the tension of the game.
"The one fantastic bit of quality was the goal but we needed more of that if we were going to win the game."
Source: PA
Source: PA