His description of a Navy SEALesque operation the government of Belize put in place to poison a bunch of stupid dogs leads me to believe this guy has a tenuous grasp on reality. And he has a history of violence. Oh and he's apparently been really big on research chemicals as well? Yeah, his mind is fried.
While I have zero knowledge of this particular situation, I've spent a fair amount of time in Central America and "corrupt law enforcement does something creepy" really does not seem all that far fetched to me. The rule of law does not work the same way it does in the US or western Europe - I too would hesitate to trust the legal system, especially if I had been around long enough to piss off (eg fail to bribe) the local authorities.
Of course McAfee may very well be a nutter. These are not mutually exclusive propositions.
This is more about meth/meth derivatives than any work on some replacement for antibiotics or whatever. Research chemicals are bad fucking news and for every one discovery of something like LSD there are hundreds of newly-discovered chemicals that will happily get you high or keep you awake, while scrambling your brain and turning you into a literal crazy person who: thinks the government is poisoning his dogs; blacks out and kills his neighbor.
I sincerely doubt that.