Well, that 'fact' isn't very factual. The 'conservative' justices dissented from the majority opinion, but that doesn't mean that their rendering would have made Aerio's practices legal.

In a nutshell, the dissent would have also ruled against Aerio, just for a different reason than the majority. This sentence from Scalia's dissent should put things in perspective:

"I share the Court's evident feeling that what Aereo is doing (or enabling to be done) to the Networks' copyrighted programming ought not to be allowed."