I queried the release web service using the disc ID from the example in the Disc ID documentation (http://wiki.musicbrainz.org/DiscID) and found that the artist element under every release element was the same, "Nits":
http://musicbrainz.org/ws/1/release/?type=xml&discid=lwHl8fGzJyLXQR33ug60E8jhf4k-

Obviously these artists should all be different as you can see when doing the same query on the website: http://musicbrainz.org/discid/lwHl8fGzJyLXQR33ug60E8jhf4k-