Los Blancos conceded three penalties and an own goal after going ahead through Karim Benzema at Mestalla.
Courtois said, “Three penalties against us, the second goal is bad luck… We started well, but sometimes we don't go up and we fall backwards. The first is a penalty, I stop him (Carlos Soler), I don't know why he gets to take it again. He puts it in even though I'm close to stopping it.
"At halftime we motivated ourselves to turn it around but then we suffered two penalties. Marcelo arrives first but Maxi screams louder. Ramos's hand is bad luck."
He added: "We are being more offensive, also in pressure and so a goal can happen. From a long ball, you have to have a union like we had after the quarantine, when they barely scored goals.
"Apart from the unlucky goal, there are three penalties, it's bad luck."