??? If I understand correctly, we have been talking of just close-up slow-mo death sequences.
Problem is, ALL the sequences in VATS after you go 'OK' are slow-mo. It's not just the moment when the enemies heads are blown, there's a slow-motion shot of the character shooting and even freakin' reloading.
And the character is, of course, sped up when you compare it to the enemies which move at normal speed.