Bolton boss Coyle unhappy with West Brom goal
Coyle described the lively 1-1 draw as a "terrific advert for the Barclays Premier League" but felt that Peter Odemwingie had been in an offside position when he received the ball before sending it in for Morrison.
"The disappointment for me is that with the goal that they scored, Odemwingie is clearly offside in the middle of the park when the ball is played through," Coyle said.
"Whether the assistant referee felt that another player with him was going to pick the ball up, I don't know.
"But he has allowed play to go, Odemwingie picked the ball up and although, I have to say, he showed tremendous quality in cutting back and sending a pinpoint cross in, we paid a heavy price for a decision that should have been stopped at source."
He continued: "I think he (match official Peter Walton) is a very good referee and ultimately that decision is not for the referee - it is for his assistant.
"We have a very good relationship, so there is no problem at that end. I will go now and ask the question of the assistant referee why he didn't flag, but I don't want that to take away from what was a terrific game.
"Ultimately it has cost a goal and you don't know how things would have panned out if it wasn't given at that point, but what I do know is that we looked a very good side for large periods of that game."