It's a case, actually one of 2 cases in which an Alaska Airlines pilot flew a right base to a nontowered airport. The pilot's defense was that it was far enough out to be outside the normal traffic pattern and essentially a right turn to a straight in approach. The cases are often cited for the proposition that anything within 6 miles of the airport is in the traffic pattern; others say is really stands more for the proposition that the size of a traffic pattern depends on the airplane involved. Either way you want to read them, though, it's pretty clear the left turn rule applies to nontowered airports that don't have a tower, operating or not.
Only one of the cases,
FAA v Boardman, is available on the NTSB website. The one that talks more extensively about the issue, Rivard, is discussed in Boardman but is just old enough to be outside the group collected on the public site.