JoinPhrase filled with " &" but no additional artist?

If you look at the JSON result for this release, you can see that the tracks have a joinphrase filled with a " &" character, but there is no additional artist.

(The recording artist-credits seems to be correct, I can’t find any joinphrase character.)

You can easily see the same missing artist credit after the & sign at the release page

Was this just a bad/incomplete import from another source?

The track artist credits are incomplete. Discussion at

Which discussion?
Do you know any ticket#?

I think this is the one.

It’s a duplicate, and was closed/fixed a long time ago. I don’t know why the original editor didn’t go back and fix the release, unless he wanted to leave it in place as an example of the error.