without any data and careful analysis of that data, his opinion on how to hire is worthless.
it's somewhat disturbing that he likes to use the STAR framework, which normally leads candidates into artificial responses. is there any reason to believe that this framework leads to better results?
http://www.londoninternational.ac.uk/ offers courses with respected accreditation and (limited) study materials. the cost is tiny compared to tuition in the usa. no real STEM courses though.