Witness Reverend Jeff Hood told reporters he saw a man ‘struggling for their life’ for 22 minutes as Smith became the first US death row inmate executed by nitrogen asphyxia
“Kenny just began to gasp for air repeatedly and the execution took about 25 minutes total.”
You have absolutely no evidence that this is true, you're just parroting after-the-fact propaganda while entirely ignoring the good science on offer in this thread.
Ignoring science? Nope. If They implemented it correctly there would have not even been a struggle nor a groan as the oxygen would have been replaced by nitrogen in the blood and death would have been without a whimper. As it was even without the correct implementation since it seems the nitrogen was mixed with some oxygen or unconsciousness would have been within seconds, he was aware of no pain at the time of death as he was unconscious. Unless you are trying to claim that he was supernaturally aware of pain through some other means than his consciousness.
Except for the 22 minutes of struggling to breath. Unless you're discounting those by saying he was unconscious the moments before his death. If that's the case, most forms of what we consider painful death are after at least a few moments of unconsciousness.