In what circumstances will remand a defendant be remanded in custody pending further review?

People v. Mora (1995) 39 Cal.App.4th 607, 615, 46 Cal.Rptr.2d 99 ["If the punishment mandated by law ... is so grossly disproportionate to a particular defendant's individual culpability to constitute cruel or unusual punishment ..., a court has authority to prevent the imposition of unconstitutional punishment."].) Nevertheless, they contend remand is unnecessary because whether a sentence amounted to cruel or unusual punishment is a question of law that we may decide ourselves on de novo review.