McCarthy claimed Scharner was "taking the p***" after he held up his match shirt and displayed what was written underneath on his T-shirt in the closing stages of Albion's 2-0 win.
But McCarthy has since discovered Scharner had only a Baggies crest and the words 'West Bromwich Albion' displayed on the T-shirt.
McCarthy said: "I'm sorry I even got involved in that because Scharner played well.
"There was a lot made of it before I even knew what was on the shirt.
"Having found out there was a West Brom badge on it, I thought 'What the hell?' and it didn't bother me.
"People forget sometimes that I've been a player, and when someone does that to you when you're hurting, those are the kind of things that upset you."
Scharner revealed after the game that the crest and words had been inked on the T-shirt by his son.
McCarthy this week lost out in his bid to bring in James McFadden as the forward signed for Everton, but McCarthy stressed it was not money which turned the former Birmingham man away from Wolves.
McFadden, who was a free agent, trained with Wolves before opting to join the Toffees for a second spell at Goodison Park.
McCarthy said: "We never lost him - he chose to go to Everton and, as far as I'm aware, there was nothing in it in terms of the finance of the offers.
"They offered him a deal to the end of the season, which was the same as we were offering him.
"No one blew us out of the water in terms of the deal, it was just that he wanted to go there, and good luck to him."
Source: Team Talk
Source: Team Talk