Tony Pulis blamed a lack of good fortune and a loss of concentration for West Brom’s 3-2 defeat at home to Everton on Monday.
Saido Berahino and Craig Dawson had put the Baggies in charge, but Romelu Lukaku scored twice and also set up Arouna Kone for another as the Toffees recorded a 3-2 win at The Hawthorns.
The Baggies had previously kept 14 clean sheets in 24 top-flight games under Pulis and remain the only side in the Premier League not to concede an away goal.
But defeat left them winless at home in the league this season and Pulis said they were on the wrong side of the decisions.
He felt Kone was offside before his equaliser while the ball struck Lukaku’s hand before he bundled it in from close range six minutes from time.
He said: “The second goal is offside, it’s marginal but it’s offside, they just tell me now Lukaku has handballed it for the third one. They have had a bit of fortune and we haven’t but when you are 2-0 up you should see the game out.
“Saido’s goal was the only bit of quality in the first half, we got the second one and then we just switched off.
“I don’t think we touched the ball, I think we were still celebrating the second goal without concentrating.”