The sole question the U.S. Supreme Court agreed to consider when granting certiorari in a case where a bankruptcy judge — answering a mixed question of law and fact — ruled Robert Rabkin could vote in favor of a Chapter 11 cramdown, because Rabkin did not qualify as a “nonstatutory insider,” was “how an appellate court should review that kind of determination: de novo or for clear error?”Acknowledging that “mixed questions are not all alike” — because “some …