Carlo Ancelotti and Leonardo blamed the early dismissal of Mamadou Sakho for PSG's failure to beat Montpellier.
The France defender was sent off just 10 minutes in for a last-man foul on Gaetan Charbonnier, a decision the team leaders both felt was unjust.
PSG nevertheless took the lead through Maxwell but had to settle for a 1-1 draw after Remy Cabella equalised for reigning Ligue 1 champions Montpellier, who also finished with 10 men after Younes Belhanda collected a second yellow card.
Ancelotti told psg.fr: "It was a difficult match. I think it was difficult to digest the fact of playing with 10 against 11.
"Sakho's red card was not merited, but after that we played well with lots of intensity, energy and good organisation.
"We played like a team and at the end we would have deserved to win. It was a draw but the team spirit was good."
Sporting director Leonardo added: "It was not a good result. Of course, with 10 against 11 for an hour it was difficult. The forward made the first foul in the incident with Sakho, then both players came together. You cannot give a red card for that. After 10 minutes, it ruined the match.
"I am not against the referees, but that determined the match too much. We do not demand anything special, just to have the same treatment as everyone else."