Just a minor point of order, Mach is only calling him "Dude" as that is his username - "fpvdude".
Also, I am often PIC from the right seat - the quote and reference you provide (and ask us in a holy manner to "behold") does not support a suggestion that it "must" be done from the left seat, but, as you allude, CASA may have a different (incorrect IMO) view.