Definitely a hot-water situation. Someone could deliberately transmit 'illegal' material through the Tor network between two machines belonging to themselves, monitor the transmission and report the server owner for transmitting it illegally. Fundamentally anyone could target a mark and get their system shut down.
As has been said, this appears an easily defendable case. On the other hand, if upheld, it would have major ramifications for *anyone* running a public facing network. The theoretical ability for a third party to *legally* get an entire infrastructure network shut down (on the simple pretext of retransmission of data via the infrastructure of that company's network) through one illicit act is quite scary.