Bolton boss Owen Coyle was unhappy that West Brom's equaliser was not ruled out after Peter Odemwingie came back from an offside position to set up James Morrison's goal.
The Trotters chief saw his side go 1-0 up in the second half after an expert lay-off from skipper Kevin Davies found Johan Elmander who steadied himself before firing the ball past Scott Carson.
However, the Baggies pulled one back when Morrison headed home an Odemwingie cross in the 78th minute which Coyle believes should never have stood.
"The disappointment is the goal that West Brom scored, it's clear in the build-up Odemwingie is offside," the former Burnley boss told Sky Sports.
"I don't know if the assistant referee was waiting for (Giles) Barnes, the wide player, to touch it.
"But it was Odemwingie who has clearly picked the ball up, cut back and delivers a great quality cross - take nothing away from that and the finish from West Brom - but he was obviously offside to begin with, so it should never have happened."
Bolton had several opportunities to clinch the three points when Gary Cahill saw his first-half header fly over the bar and Martin Petrov spurned a superb chance to find the net as he blazed wide.
However, Coyle has been heartened by Bolton's impressive displays this season and came away with several positives from the 1-1 draw at The Hawthorns.
"I think we showed again we're a decent side and we should eventually turn those draws into wins, there's no doubt about that," he said.
"I thought we really upped our game in the second half, scored a terrific goal and looked all set to go on and win the game, except West Brom came back and threw everything at us."
Coyle also praised the performance of Elmander, who notched his fourth goal of the season, adding: "He's got a terrific partnership with the skipper Kevin Davies, who is a terrific leader, so they're a decent combination, there's no doubt about that."