I. May an appellate court, consistent with due process, relieve a government party of its burden to show that a favorable error is harmless, decide the issue sua sponte, and thereby assume the government party's burden itself?

II. If appellate courts may assume a government party's burden to show that a favorable error is harmless, is doing so mandatory or discretionary?

III. If doing so is discretionary, what limitations do due process or other considerations place on when appellate courts may exercise that discretion and when appellate courts should exercise that discretion?

Whether an appellate court may relieve a government party of its burden to show that a favorable error is harmless, decide the issue sua sponte, and thereby assume the government party's burden itself