One problem these 'it was just a party drug they took willingly before sex' defenders have is that a few of the accusers actually did not have sex with him.
For example, one woman did not drink at the Cosby family Christmas Eve party, so even according to her, when he started to molest her and she fought back, he stopped. He did not proceed to have sex with her. So did she know and consent to taking drugs before sex with Cosby when she unwittingly failed to take the drugs and fought him off?
Another woman for example said she did have a drink but was drinking slowly enough that she noticed that her drink was drugged before losing consciousness and started to scream at Cosby and attack him. According to her, he grew so mad he shoved her out the door. So did she consent to take the quaaludes to have sex with him, even though she fought him off and didn't have sex with him?
This does look like a pattern of Cosby putting drugs in women's drinks without their knowledge so that they would have no memory of being raped, and not proceeding if they were still aware enough.