It seems Mr. Spencer has made some strong accusations against UL and NEMA without any backup material. UL and NEMA have a reputation of providing good safety advisories for the general public. By following acknowledged standards, we, the public can at least feel somewhat safe.
However, I am not yet convinced that AFCI breakers are proven beyond all doubts. I feel the NEC should have held off a while until all the test were complete and all the data is on the table for review (and maybe they thought that was the case).
Just my thoughts at the present time.