West Brom boss Tony Pulis vowed to talk to James McClean if he finds the midfielder crossed the line.
The former Sunderland man sparked anger after he celebrated in front of the visiting fans following the Baggies' 1-0 win.
He claimed he was hung out to dry by the club following his refusal to wear a Remembrance Day poppy in 2012.
Saido Berahino cashed in on Costel Pantilimon's second-half error to condemn Sam Allardyce to defeat in his first game in charge of the Black Cats.
Republic of Ireland international McClean, who left Sunderland in 2013, was jeered by the visiting fans all game and while Pulis did not see the incident - which saw McClean confronted by Danny Graham and Lee Cattermole after the final whistle - he insisted he will study the evidence.
"Let me have a look at it first," he said.
"I'd heard a roar or whatever and didn't know whether the players were involved in something.
"If he's out of order I'll speak to him.
"He played really well today, James. He's settled in really well and is a smashing lad and the lads have really taken to him, he's a really nice lad.
"He's not the sharpest tool in the box, and that's not being disrespectful to him. But he's a smashing lad."
Victory moved Albion seven points clear of the bottom three and Pulis admitted the win was vital.
"It was a tough game," he said. "The good thing for us was getting a result after the Everton match when we were 2-0 up and then conceded three goals in the last 20 minutes, which was a real kick in the stomach.
"For confidence as much as anything else it was important to come and win here."
Boaz Myhill saved from Billy Jones in the first half but the game was instantly forgettable until McClean's fist-pump gesture to the visiting fans.
It left Sunderland second bottom and they could fall to the foot of the Premier League table if Newcastle avoid defeat to Norwich on Sunday. But Allardyce claimed Berahino fouled Pantilimon for Albion's winner.
He said: "We'll probably get a ticking off for surrounding the referee after the goal went in but I could hardly blame them for that because the referee has made such a big error. If we get a double punishment it'll be pretty difficult to take.
"It wasn't our fault we lost the game, I thought it was his fault on a decision he made not to give a free kick."
Sunderland face Newcastle at the Stadium of Light next Sunday with both teams yet to win in the league this season, and Allardyce hopes the Black Cats can continue their winning sequence against the Magpies.
He said: "All they have to do is carry on from five times before, they have been in this position before. The last five games they have played Newcastle they have won.
"They didn't look like conceding a goal today which is a great platform for us to build on."