Napoli coach Carlo Ancelotti was left frustrated after their 2-1 defeat to Juventus.
Ancelotti says the dismissal of goalkeeper Alex Meret hurt them.
"It's controversial. He certainly didn't catch him, I can accept it was punished for an attempted tackle. Then you have to take into account where the ball was going, where Allan was," Ancelotti told Sky Sport Italia.
“Seeing as we have VAR technology, why not view it in totality? It was not a very clear red, as Cristiano might not have been able to get on to that ball anyway. It was going towards the corner flag.
“Meret did not touch him. After that, you have to consider all the other elements. The red certainly changed the game. The only two things we got wrong were the positioning on the wall for Pjanic's free kick and the corner marking on Emre Can.
“Piotr Zielinski didn't jump in the wall and the ball went over his head. It's destiny, because Milik was meant to be in the wall…"
The far taller Arkadiusz Milik was substituted moments earlier to allow David Ospina to come on.
“You have to make decisions in a fraction of a second, it was still 0-0, so we thought Insigne could make more of the counter-attack and play ball to feet. That's why we chose to take Milik off.
“I wouldn't say there are regrets this season. Juventus have been extraordinary and never allowed us to get near them. Nonetheless, this is a performance that gives us reassurance for the immediate future and going further forward.
“I was genuinely surprised by how superior we were to Juve once it went to 10 against 10. It showed how much quality there is in this team, we've got to become more and more convinced of our own capabilities.
“We are having a positive season, changing some tactics and bringing new, younger players in. We must trust our own qualities. We cannot win a game the way Juve did tonight, as we have very different strengths.
“Juventus have great temperament, organisation and individual duels, whereas we have more technique, quality and have to focus on those strengths to win."
