It is 2023 not 1623. The man was mentally ill, not mentally retarded. There is mention of drug abuse, but there is no definitive link to this event. Perhaps, the drug abuse may have caused the delusions or it may have been an attempt to self medicate. The incompetent journalist who tossed out the reference without context, or background on the person, does not know and neither do you.
If the person is delusional, he requires appropriate treatment and if a danger, institutionalization. Hanging him upside down and beating him until his buttocks bleed will not cure the man if he is delusional. He may not even know what he did after his delusion dissipates. It might satisfy the carnal lust of a primitive and backward society to beat this mentally ill person, but it will neither rehabilitate the person or prevent future incidents.
There is one solution and that is to execute the man so he does not have the potential to do harm in the future. Perhaps if the nation's mentally ill could be executed on a regular basis, this would address many societal problems. Hopefully, the Russian, Iranian or Chinese parameters would not be used as they are currently employed to dispose of political dissidents in the respective countries. I expect that Thailand could easily find 10-50 mentally ill in any given week, and much more if the net was expanded to include western farangs. Perhaps you could volunteer to be on the euthanasia/ death squad. There was a fellow back in the 1930's who devised a special method of using a truck that fed the exhaust back into the cargo bay, so as to asphyxiate the passengers. Maybe you could do that. What do you think, or are you really into beating mens' buttocks until they bleed?
Because he knew he would be ridiculed for his hypocrisy. North Vietnam intentionally violated the Paris Peace Accords. The North Vietnamese negotiated in bad faith. The USA respected those Peace Accords. The USA was withdrawing military material and personnel as per the agreement, but the NVA were sending personnel and material into south Vietnam, and Cambodia.