If you botched an execution, then the convict should be commuted to life sentence or even pardoned if they suffered greatly. In addition, the people who botched it should be put on trial for malpractice and fined/jailed.
The executions aren't done by doctors, as that goes against their hypocratic oath. It's not even done by nurses in a lot of cases. They're done by people who have barely any training. Botched executions are a dime a dozen because of this.
To be clear, I am against all forms of capital punishment. It's barbaric and has no place in 2023.
I think you may be underestimating the types of people on death row and the crimes they have committed. Which is understandable as most people don't really encounter people like that and don't really consider the true horror the crimes committed
These people (and I'm assuming guilt has been correctly assigned here for the purposes of the argument) have committed horrific crimes. Raping and murdering children, wiping out entire familys, abudction then torture then murder, those kinds of things.
For example, the case of Johnny Johnson: https://youtu.be/ntpK9D3935o (warning: this crime is about as bad as it gets and is described in detail here). I won't describe the crime here. The video is worth a watch if you're curious but you have been warned.
There is no pardoning that. Ever. Under no circumstances should they ever be allowed to walk among us ever again. Even under the strictest possible supervision.
These crimes are so awful that we simply cannot forgive, and these people cannot be rehabilitated, and no second chance should be granted.
Death penalty or not (to which I can see both sides of the argument and is probably still something to be debated but isn't the point of this comment) I can't envision any solution of pardoning these criminals is ever acceptable.
People on death row have committed horrific crimes. They aren't there because they stole something. They are there because they ended or destroyed lives.