e.g. http://beta.musicbrainz.org/edit/relationship/edit?returnto=http%3A%2F%2Fbeta.musicbrainz.org%2Frecording%2F12b182f3-5483-47d9-996e-41498b3b2fde&type1=url&type0=recording&id=1808

Lookup a different recording with the same name and select it. There are no visible changes, so you have no way of knowing that it's changed and you can easily change it to an entirely different artist by accident, as I explained in MBS-4528

Another example is http://beta.musicbrainz.org/edit/relationship/edit?returnto=http%3A%2F%2Fbeta.musicbrainz.org%2Fwork%2F2c6e2d1f-9bc2-3c42-97e6-d5eee2eecd7f&type1=work&type0=recording&id=224229

Neither the recording artist nor the work disambiguation comment are shown.