After http://beta.musicbrainz.org/edit/37396532 artist credits disappeared from recording (or aren't currently shown correctly). This happened when I updated artist credits with release editor to some recordings. Artist credits also disappeared from track list.
Tracklist on http://beta.musicbrainz.org/edit/37396540 is having artists for all tracks but 2 minutes later we see on http://beta.musicbrainz.org/edit/37396548 that artist credits (on old tracklist) don't match with my earlier edit.
Currently on release editor/recordings tab "Paavo Heininen" is an artist for Arioso, op. 16. That wasn't artist credit before or after my edit and I believe this data is currently sourced from track list and not from the recording.