Google Torrents is using the Google Coop platform. Google Coop allows people to create customized and personalized search engines.
Even though it is not very useful, it does show that it is easy to find torrents with Google. Google even has a filetype command that helps you to find .torrent files.
A couple of months ago the BitTorrent search engine Torrentspy used this argument in a motion to dismiss a lawsuit initiated by the MPAA. Torrentspy said that that everything they do, Google can do better.