Air forces around the world use nitrogen inhalation to simulate the effects of hypoxia caused by high altitude decompression for training.
From that we know for a fact that it is absolutely painless all the way to loss of consciousness.
We also know that it is perfectly safe to have people in the same room who do not participate in the exercise.
And we also know that you don't need a perfectly fitting mask if the had mixture is supplied in it at positive pressure.
The author is reaching at straws for arguments so he makes them up. He's imagining possible problems or downsides and calls them as immediately disqualifying without ever bothering to look for their validity or solutions.
I'm against capital punishment. But if it has to be done this seems to be the least cruel method to do it by far.
it's hard to imagine complications with electricity or lethal injection as we all have electricity in our houses, and administer injections hundreds of times per second across developed countries - and yet a significant amount of times either are used in the rare cases of execution they are bungled causing distress, pain and delayed death of the condemned person to both the victim, the executioner and the witnesses.
I guess irony doesn't travel online. If it's easy to imagine complications there, why is it incorrect to imagine complications with execution via gas inhalation?