Why was it illegal to /follow/?

I am not an expert; and could be way off base, but I would assume, that knowingly following a corporate policy that is against the law, would be illegal, even if you aren't the one who implemented it. I am also making the assumption from what I read that everyone knew what this policy really was, from the way the emails between the two companies framed things. Again, this could be off base as well.

It's roughly the same as if these companies colluded to drive down the price on components.