Tykes boss Gerhard Struber thinks the Latics could have been down to eight men at the final whistle
Danny Fox was sent-off in the 71st minute for a high tackle on Elliot Simoes.
The Latics left-back Robinson was shown a yellow card for a strong tackle on Kilian Ludewig in the first half, while forward Gelhardt was cautioned moments after coming on for a tackle on Callum Styles.
Struber, who side sit bottom of the Championship but only three points from safety, said: "I think it was a red card for Fox, but I also think the tackle on Styles was a red card too. It was two footed.
"I think the tackle against Ludewig maybe was also a red.
"For me it was a clear red for the action against Callum Styles in the second half.
"That could have made a big difference in the last 15 or 20 minutes, having that overload situation against nine men.
"We had to win this game."
Despite only picking up a point, Struber was very happy with his team's performance and felt that they just about shaded it over the 90 minutes.
"I am very happy with many parts of the performance," he said.
"I think we had so much control and many chances.
"This is our topic at the moment. We can't make the most of our best chances.
"This is the issue. Our strikers are not sharp enough to score goals."