In stoppage time and with the Sky Blues trailing 1-0, Freddie Eastwood had a shot inside the penalty area, the ball hit a hand. Initially, referee Steven Cook from Surrey awarded a corner but the assistant on the Tescos Stand side spotted the handball and summoned him.
After a discussion which saw the Barnsley players including a heated Robert Kozluk who insisted on showing the left side of his stomach where he claimed the ball hit, a penalty was awarded to City and Elliott Ward scored to earn City a point.
"We've looked at the penalty two or three times and if it didn't hit they lad's hand then it was going in the back of the net," said Chris Coleman to the club website.
"Freddy had a bit of a bad night but he kept going, kept looking for the ball and he won us the penalty. Had he not won us a penalty he would be celebrating a goal so I was pleased with that."
Speaking to the Sporting Life, Coleman said: "When it happened I thought it was a penalty, then I wasn't so sure. But I have seen it in slow motion and there is no doubt whatsoever, he had his arm out."
Barnsley boss Simon Davey said to the Sporting Life after the game: "I don't know if it was a penalty but all I've got is a referee six yards away giving a corner and a player in the dressing room with a red mark on his chest."