Note that he never admitted to drugging anyone, important caveat.
To put this in reference, it's like me being convicted of murder for saying that I got bullets with the intent of killing someone, regardless of me doing it. That they ended up dead should rightfully cast me as the prime suspect, but that alone is hardly evidence enough to prove that I did it.
I say this not to defend Cosby, but to draw into question what's supposedly different between Kavanaugh and Cosby that we apply two different sets of evidentiary standards to consideration of their cases. Recency has little to do with it, physical evidence has little to do with it (otherwise Kavanaugh's lie about being a HS virgin looks really bad when you see his yearbook), so what's the difference? On one side we believe the accuser, on the other we attribute political malice. Seems like something substantial differs between the two that provides major concerns with whether or not justice was actually served in this case.