Nitpick: The Governor of Texas cannot commute a death sentence. He can issue one 30 day stay, but ultimately it is up to the Board of Pardons to commute a death sentence.
Second, isn’t catching a spouse in open adultery THE textbook case of what makes the killing manslaughter instead of murder? (Assuming no intervening circumstances)? The old “killing while done in response to a provocation or in the heat of passion” or the new “done while under extreme emotional distress”?
My guess is that while the good doctor would do many years in prison, he would come out with a life to live on the other end…
What if a guy does a Timothy McVeigh by setting off a huge bomb next to a crowded office building and walking away, killing over 5,000 people. While on death row, he finds a drug that puts everyone in perfect physical and mental health with no side effects.
In other words, what would we do if we took the hpothetical in the OP and stretched out the premises to unbelievably ridiculous extremes? I don’t know.
If there’s a mitigating circumstance that prevents someone from being a threat to anyone who hasn’t gone out of their way to fuck him over, he should not be executed and I’m fine with releasing him at some point.
If there is doubt that he is guilty (basically anywhere between what is called “beyond a reasonable doubt” and “we captured him running away with the murder weapon”), he should not be executed, but should not be released until his guilt falls below that “beyond a reasonable doubt” threshold.
If he’s more useful to you alive than dead, he should not be executed, but should not be released.
If none of these apply, go ahead and kill him.
Either execute him or put him to work in prison. Freedom is unacceptable.