Referee Paradas Romero was the centre of attention, sending off two Real players and both manager Jose Mourinho and coach Rui Faria in a bad-tempered 1-1 draw at El Madrigal.
Madrid defender Pepe was later revealed to have abused Romero in the tunnel afterwards and the dismissal of Mesut Ozil for ironically applauding the sending off of Sergio Ramos appeared particularly harsh.
But Brazil left-back Marcelo said that his side must focus on improving their defending from set pieces, and not on criticising referees.
"We are doing our jobs but, sometimes, referees hurt us. We have to continue working," he said. "We must improve on many fronts. In the last two matches we conceded from set pieces. This is not good enough.
"But we are still ahead and we will continue working hard."
Marcelo also pointed out that - despite consecutive draws seeing their 10-point lead cut to six - his side are still in pole position to win La Liga.
"We should be happy they still have a six-point lead over Barcelona," he added.
"I think any team would like that. We have to stay calm - it was a tough match but we are fine.
"We didn’t win but we didn’t lose and team spirit is good."