It's transformative. Not aimed at exact reproduction, so not in the scope of copyright law.
They participated in uploading the files as part of the downloading the torrent from other peers. Their use of the BitTorrent protocol to acquire these files would not have been transformative.
I think you misread. There is nothing transformative about bittorrent automatically sharing parts of a file you're downloading with your peers.
They participated in uploading the files as part of the downloading the torrent from other peers. Their use of the BitTorrent protocol to acquire these files would not have been transformative.