borg's belly clears out any outdated entries. I'm guessing that there was a really old entry (probably for a certain user who would never take the hint) and today was the first time someone viewed borg's belly since that entry expired.

Or, if you prefer, someone didn't bother to test that the old and new code returned compatible values for the edge cases such as empty vars. (:

Works correctly for truly empty vars (vars=""), but not for cleared ones (vars="==01:H"). Will see what I can do.