Yeah, that basically it. If you download the torrent, your ip is visible, they don’t care if you upload or download. As far as they’re concerned, if your IP is there, they’ll snatch it and send you a letter.

It’s not possible to ‘not upload’. While you are downloading, you are simultaneously uploading. If a rightsholder or copyright troll is monitoring a torrent, they don’t care home much you have downloaded or uploaded. If you’re in the swarm, that’s good enough.