My bet is that the Supremes will ignore this case.
It seems obvious to me that when the prosecutor proffers that something is confidential, they shouldn’t be able to turn around and use it against you. Seems like self-incrimination by entrapment or fraud.
This is true even if Cosby is a famous and inveterate sexual abuser/rapist of women.
So, I think that procedurally, Cosby had to be let off. It’s too bad the prosecution didn’t think it could make its case the legal way.
Bingo, they knew using his testimony in the civil case would end in him wining an appeal but they did it anyway.
I’d prefer they take it and confirm that a prosecutors word - especially written - is binding.