As I said, in judicial execution, it's not the induction agent which kills, it's the combination of the other two drugs. The induction agent is intended to minimise the risk of the victim struggling and because the muscle relaxant which stops breathing can cause pain and distress. Some of course would think that this is perfectly okay, but that's a whole different argument. Failure to induce anaesthesia competently - e.eg because the cannula is not inserted correctly into a vein can result in a slow and distressing death because the other drugs will eventually work even if not administered intravenously - but the victim will have been conscious for most of that time. I doubt if someone is incapable of even inserting an IV cannula correctly, that they would have the skills to insert a central line. I don't know that too many doctors would be willing to participate in judicial executions.
My husband is an anaesthetist and I have worked in operating theatres for most of my working life, so I know plenty about anaesthesia. The induction agent is only intended to render someone unconscious, so that any other necessary drugs, such as a muscle relaxant for certain types of surgery where paralysis is required, can be administered without discomfort or distress.
Your friend is correct though, that reversing the anaesthetic is the really clever part - and that is particularly the case when a muscle relaxant or any form of opioid or benzodiazepine drug has been used.
