See e.g. http://test.musicbrainz.org/release-group/5d299f1e-0c0e-3278-a3fb-49de85e9ce20/edit
where a trailing link phrase is used to add a closing parenthesis ) to the artist name.
When doing a (possibly unrelated) edit, the artist credit editor will drop the trailing ), causing accidental edits like http://test.musicbrainz.org/edit/13876122 where information is lost.