The Brazilian centre-back conceded a first half penalty after dragging down Lucas Hernandez during a corner.
French striker Antoine Griezmann scored from the resulting spot kick.
Speaking on ITV's Champions League highlights show, he said: "It's madness really. It's a form of cheating.
"Why he's doing it is beyond me. He's lazy and he's letting his team-mates down. He knows himself. There's no need. We see a lot of that going on, so I'm glad he got punished for it. It's a form of cheating."