A feed event for a CritiqueBrainz review of an album should link to the release group on MusicBrainz (here: "Deadbolt"), but the website renders a broken /recording link which contains the release group MBID (which can't be found, of course):

This probably happens because all feed events are shoe-horned into a "listen" object, which always links to a recording. Note that the recording_mbid field also contains the RG MBID:

{
  "listened_at": -1,
  "track_metadata": {
    "track_name": "Deadbolt",
    "artist_name": "",
    "release_name": "Deadbolt",
    "additional_info": {
      "artist_mbids": [],
      "recording_mbid": "ad5bc068-a0a4-4c8e-b0cb-c69d806cd052",
      "release_group_mbid": "ad5bc068-a0a4-4c8e-b0cb-c69d806cd052"
    }
  }
}