Appeal to authority fallacy. It has to actually be in the book. McCarthy has shown to make up his own rules all the time.
NFL fallacy. my term, made up. not all sports are as specific as the NFL.
in the NFL, there are like 20 pages on what different players can do with his hand, feet, within 5 yards of the end zone, within the tackles, etc, etc. specific players.
in other sports, including mma, many rules are left vague or NOT in the rule books, and then taught at seminars, and left up to the ref.
did you know that the last rule in baseball is "anything not covered by this rulebook is up to the discretion of the home plate umpire?"
so unlike the NFL, MMA rules only have a vague "back of the head" rule, and then
define it elsewhere. whereas the NFL would have a 20 page description.
because of this delta, you are incorrect in saying "It has to actually be in the book!" a shitton is left up to the ref. by design.
fact is, BJM was there before the rules, was there to help write the later rules, partook in the debates about the rules, understood the nuances of the intent of the rules, has taken the seminars on the best way to interpret and implement the rules, has taught the seminars on the best way to interpret and implement the rules, and frankly has probably forgotten more about the subtleties of the rules than you or i will ever know.
is he perfect? no. is perfection possible? no. but it's not nuthugging to point out that he's the most qualified expert in the sport. when you're sick, you don't go to a plumber for advice.