The Barcelona defender has claimed the referee was too afraid to caution the Portuguese during Wednesday's clash with Real Madrid for fear of seeing him suspended
The two rivals played out a 1-1 draw in the first leg of the tie, but the Brazilian feels the public's desire to see an individual battle between the Portuguese and Lionel Messi influenced the officials.
"We already know how he operates and how all this plays out. There's nothing to be done. People talk and reject things, but I still don't understand how Cristiano didn't get a yellow card," he he told reporters.
"If it had been me it would have been a red card. But if he missed the second game, then there's no Clasico and that's not interesting to lots of people, as there would be no battle with Messi.
"I'm saying what I think, as I don't owe anything to anybody."
The Brazilian reportedly subjected to racist chants in the Spanish capital, and claimed that football is fighting a losing battle against discrimination.
"I didn't think about leaving the pitch, but it's harassment. It doesn't only happen at the Bernabeu, but at all the stadiums we go to. People are fighting to see this doesn't happen but it keeps happening.
"It's a shame. You can be playing well or not, but the people that go to the game should support their team. Racism in football is a battle that's lost, until drastic measures are taken.
"I've been in Spain for 10 years and it's still happening. This isn't one of the places I feel most like a victim. There are worse; in happens in general all over Spain.
"Sanction the club and the team, but not with €1000 fines. You have to go a bit further. They should set an example and look at England.
"There the measures are strict, but it's hard to find things to improve on. Manners don't exist at football stadiums."