The sides drew 1-1 in Naples to leave Group C wide open following Liverpool's shock 2-0 loss to Red Star Belgrade.
Juan Bernat gave the Ligue 1 giants the lead just before half-time, only for Lorenzo Insigne to equalise from the penalty spot.
Replays showed that Jose Callejon was offside in the build-up before the penalty award, while Bernat appeared to be fouled in the area on 70 minutes, but nothing was given for the visitors.
Neymar was not too concerned with the decisions but slammed referee Bjorn Kuipers' attitude towards him and his team-mates.
"I don't care about the mistakes that can happen," the Brazilian said after the match. "The referee is a human being and can make mistakes, even clear ones like the penalty.
"The way he treats players is disrespectful. What he told me lacked respect, that's why I lost control and said a few words.
"He has to respect the players. It's not because he has a whistle or a card that he is above everyone. I condemn him for the way he treated me. I hope the people above him can do something about it."