It is closer to "you think you can get away with this by following the letter of the law but not the spirit of the law." The whole point of the Supreme Court is to interpret the gray areas where the law is imprecise in its attempt to express its attempt.
I think in this case, the intent is really "if the end user goes to a lot of work to record shows, that work justifies them having their own copy of this over the are streamed stuff. If a company wants to help a consumer decrease that work, they can do so by selling devices but not services. If the company tries to provide a service, then the company is involved in the duplication and that's illegal."
I don't know if I agree with that as the basis for copyright law, but based on earlier copyright rulings, that's my perception of how judges (both the Supremes and lower) typically view copyright infringement cases when they hit the gray areas and new tech is involved. It's not a bad way to split hairs. I think in this case, Aereo is likely to be burned because they provide the service of setting up the recording of all the shows (i.e. they tell that farm of antennas what to record instead of the consumer saying what to record). Yeah, I know that's a really technical point, but I'm betting that is a part of the final SCOTUS ruling. I am not a lawyer, just someone watching this case and similar for a long time now.