The fine motor skill argument sort of falls apart when you talk about manipulating the trigger under that same "adrenaline dump"... If you can't hit a slide release, you ain't gonna be able to pull a trigger either, as its also a "fine motor skill", and nobody ever suggests you cut out the bottom of the trigger guard, make the trigger the length of the grip and use your whole hand to manipulate it! ;D
That whole idea is just more tacti-cool silliness, which doesn't stand up to scrutiny.