Stoke City manager Tony Pulis labelled the assistant referee's failure to rule out Carlos Vela's late equaliser "a shocking decision", after the Mexican stole a share of the points for West Brom on Monday.
Television replays suggested Vela was narrowly offside when Steven Reid's inswinging cross came in, but the assistant's flag stayed down and allowed the subsequent goal to stand - leaving Pulis furious.
"As a performance, that's as disappointing as we've been all season," Pulis told Sky Sports. "Give West Brom credit for coming back at us, but looking at their goal it's a shocking decision from the linesman.
"If he can't get that right what is he doing officiating at this level? They've got to get those decisions right, they're very, very important."
Pulis was further angered by an incident in the aftermath of the final whistle, as Baggies defender Jonas Olsson damaged a picture hanging in the tunnel at the Britannia Stadium on his way back to the dressing room. "The lad Olsson has smashed the picture, I don't know why," he said. "It's very disappointing when you've got a memento of this football club on the wall and somebody does that. We'll leave it to Roy [Hodgson] to deal with."
West Brom boss Hodgson admitted he was upset by his player's conduct, after a game that was physical but never appeared likely to cross the line.
"I'm disappointed, we'll pay for the picture but it takes the gloss off a bit when I have to answer questions about pretty meaningless incidents instead of the character the team showed," Hodgson said.
The former Liverpool manager was pleased to return to Stoke's ground and get a point from the game, after being embarrassed earlier in the season while with his former club.
"You've always got to be pleased when you come to Stoke and get a point, especially when you play as well as we did," Hodgson said. "It was a good team performance, I'm very happy with that and the point keeps us going in the right direction."
And the Englishman refused to be drawn on Vela's crucial goal, simply noting that, after seeing four shots in the last minute saved by Asmir Begovic, his side got what they deserved from the game.
"There was a lot of bodies in there, I couldn't say quite frankly if it was [offside] or not," Hodgson said. "But whenever you consider a goal like that you are entitled to be angry. But I think one goal is the least we deserved for our efforts."