the technique is sound, except he forgets completely about the coupling agent, not sure if that is on purpose or not. Which I am sure is the method he used here since he mentions DMF as the solvent which is the standard for those couplings.
The stuff about the columns is basic column chromatography, except he uses alumina, which is interesting, not sure if its necessary, he doesn't specify any treatment so I assume its neutral alumina.
Remember the guy hasn't done any of that stuff for 20 years, and hes not really a chemist.
Hes not trained academically/professionally, he has a degree in anthropology and sociology.
He learned his methods well, had the help of some trained chemists, and has had a lot of practice on that particular synthesis so I don't doubt his ability, and I am sure he has some basic understanding too, but hes no more than a 'cook'.
Expect nothing, Receive everything.
"Experiment and extrapolation is the only means the organic chemists (humans) currrently have - in contrast to "God" (and possibly R. B. Woodward). "
He alone sees truly who sees the Absolute the same in every creature...seeing the same Absolute everywhere, he does not harm himself or others. - The Bhagavad Gita
"The most beautiful thing we can experience, is the mysterious. The source of all true art and science."