Definitely not seconds. If that were the case, simply holding your breath for a few seconds would be enough to make you pass out. That myth comes from chokeholds, which are not the same thing, and (when done properly) don’t actually stop the person from breathing. Instead, they put pressure on the arteries, to cut off the brain’s blood supply directly.

Actual asphyxiation takes several minutes, as the oxygen in your blood is slowly consumed. For nitrogen asphyxiation, you get a wicked endorphin high as your brain realizes it’s low on oxygen and releases endorphins to try and keep you awake. (Side note, this is why autoerotic asphyxiation is a thing. People do it intentionally to get that endorphin release and make orgasms more powerful.) But your sense of suffocation actually comes from high amounts of carbonic acid in your blood; Carbonic acid is from CO2, (it’s also what gives carbonated drinks that characteristic bitter taste, and is why flat soda tastes cloyingly sweet without the bitter carbonic acid to counter the sweetness.) Since the CO2 never builds up in your system, you never get the sense of suffocation. You just get that euphoric endorphin high, then you fall asleep.

Nitrogen asphyxiation is actually how I’d prefer to go out, if I got to choose. Like if I were in a lot of pain in my elder years and simply wanted to die, nitrogen asphyxiation is how I’d want to do it. But I also recognize that at that point it would be a choice, not something the state is forcing upon me. This dude was forced into it, which means there’s a much higher chance of him panicking regardless of the method.