How do you suspect fingers become severed? As if intentionally with surgical precision? Or by more violently messy and accidental means? Do you think only a trickle of blood comes out when one of your whole digits becomes separated from your hand? How certain are you that "5 minutes" isn't going to matter in most cases? And how certain are you that in most cases there won't be "uncontrolled bleeding?"
Where do you even begin to make that sort of claim?