If your browser is set to only tab between form fields, links are not normally tabbable. For some reason the suggested recordings section of the release editor (and nowhere else, not even the same recording/artist links on the same page which aren't inside the suggested recordings bubble) are being made tabbable (happening in Opera and Chrome in OSX for me).

That means to get from the radio buttons to the "done" button, you have to tab at least 4 times for every suggested recording (add an extra tab for every additional artist in the artist credit or release the recording appears on) when that's not what you'd expect (of course, if your browser is set to tab to everything, it'll tab to links regardless).