WRONG!
Failed biology, did we? It's not lack of O2, it's the build-up of CO2. If you're breathing any inert gas -- say, nitrogen, or helium -- the CO2 gets flushed and there's no build-up, hence no urge to breathe. And since inert gasses by their nature are non-reactive, there are no unpleasant side-effects.
They've been using helium for assisted suicides for years, and if that produced any discomfort, we'd have heard about it long ago. When if fact we've heard the exact opposite. The fall asleep peacefully.
All Alabama did was substitute inert nitrogen for inert helium.
Exactly.
Going to 100% pure nitrogen creates a negative concentration gradient of nitrogen in your respiratory system and it literally sucks the oxygen out of your bloodstream.
You go out like a light.