It's still you who are recording, not the 3rd party. If I purposely hit someone with my car, the car manufacturer can't be blamed, but if I tell my driver to hit someone and he does, shouldn't he be blamed?
Not anymore than I'm driving through my driver. Aereo controls what gets recorded, not the user. They're not an agnostic tool that can be used for any purpose, like a VCR.
Oh, I would never suggest that. I think what Aereo does should be legal. But judges are supposed to uphold the existing law, not what they think it should be.