Justin Richards converted a penalty in the 55th minute only for the Cobblers` Leon McKenzie to head an equaliser three minutes later when he rose to head home Marcus Hall's cross. Cobblers midfielder Abdul Osman was shown a straight red card for a 68th minute foul.
Sampson said: "I thought the penalty was dubious. It looked nothing more than a tangle of legs and it would have been interesting to see what the referee would have done if both players had gone down.
"I'll have to look at the DVD, but from where I stood it looked as though Abdul played the ball.
"I've also spoken to some Vale officials who were sitting in the stands and they were of the opinion the red card was very harsh.
"If it looks like we would have a chance with an appeal we will certainly go for it. That's Abdul's second sending off which would mean a four-game ban and he is a big player for us."
Source: PA
Source: PA