The Frenchman was angered by the amount of stoppage time added and by what he felt may have been a foul on Union keeper Zac MacMath during Dallas' late equalizer.
The Hoops leveled the game in the 97th minute, after the fourth official indicated that five minutes of extra time would be tacked on to the end of the game. The French forward, who leads Major League Soccer with seven assists this season, took umbrage with what he felt was excess time as the visitors sought for - and found - an equalizer.
"I heard it was seven minutes of injury time," he said. "We never saw it in MLS. In the history of MLS, I don't think there is so many injury time in the game. I'm very disappointed with the referee, I don't think he was very good today."
The Frenchman also seemed to suggest that Chapman allowed play to continue on the play that led to Dallas' equalizer because he was making up for an earlier red card earned by FCD's Je-Vaughn Watson.
"I think too, on the play, there is maybe a foul on the goalkeeper and he doesn't whistle it, so it's like very, very bad for us. We of course want those three points, but I hope that he can watch the game and see how not fair he was and tried to make a good call for them because he gives them the red card.
"I'm not a referee so I don't know what they're thinking or what people tell them to do and how they have to ref, I'm just looking at the game and sometimes I'm very frustrated because maybe you say he didn't make the right call or didn't give a yellow card when he should do. He's like us and people are watching him play, and I hope he is not going to do the same mistake he did and he's going to learn from it, but tonight he really penalized us, and they scored a goal I think they shouldn't have done, because of the injury time, too much, and the fact there was probably a foul too."