Play-off hopefuls Stanley missed out on a ninth consecutive home victory but Coleman felt it could have been a different story but for some key decision from Webster.
He said: "I'm disappointed. We had enough chances to win the game but for the fourth consecutive game the referee has had a massive influence on the game."
Coleman was particularly aggrieved Webster failed to award a penalty when Jimmy Sangare tangled with Andy Procter. He said: "After a couple of minutes it should be a penalty to us and a sending off.
"He has taken our player out and perhaps it is too early for him to send him off. This referee is in the top three in the league at the moment and I'd say this wasn't one of his better games."
He added: "I've seen this referee on numerous occasions and he's very good. Maybe that was just uncharacteristic, similar to our performance. A bit insipid."