The Supreme Court held that you can't find a parent and subsidiary guilty of conspiracy under the Sherman Act because it's impossible for such entities to actually conspire. The Ninth Circuit uses that decision to hold that a subsidiary can be liable under the Sherman Act.
You might think that gets the thing exactly backwards. But the Tenth Circuit allegedly did the same thing, albeit in a Section 2 (monopolization) case, rather than a Section 1 (conspiracy) case as here.
I know a little bit about that because I published a long piece in the Stanford Law Review entitled Intracorporate Conspiracies that talks a lot about the underlying principle. I'll forthrightly concede that I never thought about how that doctrine could allegedly be used to expand corporate liability.
It's a weird world.
P.S. - The times of my postings this week will likely be a bit off, since I'm in Serbia all week, and the time change is a killer. But rest assured I'll be keeping up as much as I can.