When determining instant death damage does the Crimson Rite effect make instant death riskier?

I’ve got a Blood Hunter player now and was wondering: When determining instant death damage does the Crimson Rite effect make instant death riskier or would max HP be recovered before that math as they drop the effect upon losing consciousness? That’s a sticky situation that can vary from DM to DM. I’d always rule in the favor of the player, as the risk already inherent in using the feature is fair enough.

— Matthew Mercer (@matthewmercer) January 29, 2018