Or at least at some point?
The case that he did is made here:
Further, a couple weeks ago, people reading between the lines of a speech Ginsburg gave thought she was hinting (probably unintentionally) that she was writing a dissent:
Note I am not sure it matters one way or another. The justices can change their minds if they want. I am seeing some conspiracy theory stuff from conservative blogs that someone, somehow, leaned on Roberts to get him to change his vote. If so that would be news but so far I see no evidence for it beyond him upholding the ACA.