The video footage shows the woman remaining still, her eyes shut. The defendants' legal team argued that was proof that she had consented; the woman's lawyers said she was too scared to move.
"The defendants want us to believe that on that night they met an 18-year-old girl, living a normal life, who, after 20 minutes of conversation with people she didn't know, agreed to group sex involving every type of penetration, sometimes simultaneously, without using a condom," the Guardian quoted prosecutor Elena Sarasate as saying.
The woman's phone was also stolen by a member of the group. Sarasate argued that if they had consensual sex: "The obvious thing would be to exchange phone numbers, not steal her phone".
Today, the court did uphold the defendants' nine-year sentences and said in the ruling that "the court affirms that the sexual relations under consideration were carried out by the defendants without the free consent of the victim."
The case has drawn attention to Spain's laws on sexual violence, which activists say are antiquated and patriarchal.
Last month, in a separate case, a man and his nephew were found guilty of sexual abuse and not sexual assault or rape because the court couldn't determine that they had used violence or intimidation while allegedly forcing a woman they met in a club to have sex and take part in another sexual act.
The court determined that the men had indeed taken "advantage of her vulnerable nature, which, added to her alcohol and antidepressants, may have weakened her ability to defend herself, thus making the use of violent or intimidatory acts unnecessary," the BBC reported.