Ronaldo delivered a remarkable cameo off the bench at Camp Nou, scoring his side's second goal before being booked for taking off his shirt in celebration and then earning a second yellow card after going to ground under pressure from Samuel Umtiti two minutes later.
The 32-year-old pushed referee Ricardo de Burgos Bengoetxea in the back before heading off the pitch, meaning he could earn a longer suspension that would keep him out of Madrid's opening games of their La Liga title defence.
Ramos does not believe his team-mate was deliberately trying to con the officials, however, and suggested that they could appeal against the dismissal.
"He was a long way from me. I think it was a moment of play that unbalanced him and he didn't feign anything," Ramos said after the match, as quoted by AS.
"It could be possible to appeal because it left us without a really important player for 10 minutes. We should think it over a little more."
Ramos had earlier been caught up in a confrontation with Luis Suarez after the Barca striker won a penalty for his side by hurdling a challenge from goalkeeper Keylor Navas, who appeared to make very little contact.
"We're at high levels of tension in this type of game," Ramos explained. "For me, it wasn't a penalty. I don't think the referee blows for something if he doesn't see anything, he would have seen it clearly. For me, there was nothing."
Lionel Messi cancelled out Gerard Pique's own goal from the resulting spot-kick before stunning goals from Ronaldo and Marco Asensio sealed an impressive win for the visitors.
Ramos was delighted with Asensio and midfielder Mateo Kovacic, who earned plenty of praise for his performance in the absence of the suspended Luka Modric.
"I'm very happy for Asensio, I congratulate him, he has a natural talent and every time he comes on he makes a difference," Ramos added.
"Kovacic has a very ugly job that isn't seen, and he does it very well.
"I'm very happy with the game. We're fighting for a trophy and it's an important step."