No one.
I am confident beyond any doubt that Scalia would NEVER find gay marriage to be a Constitutional right.
It is possible that he was worried that Kennedy was ready to straight up affirm the 9th Circuit, so he found enough votes to derail an even worse outcome than we got.
It’s not like we would have necessarily had a better outcome if the court has decided the case on the merits.
Now, I do have a theory.
Captain Zero told Roberts and Kennedy “I expect a favorable outcome in zerocare and DOMA or else... I don’t care if you draw straws or flip a coin but you get me the votes!”