I've never met Frank Mentzer. I don't know anything about his reputation. All I know is that he was responsible for BECMI and Temple of Elemental Evil. With that in mind, I find the statement below from 1982's RPGA module R-1 'To the Aid of Flax' to be ponderous.
Has anyone else ever gone 6 years in a single campaign and not created some sort of house rule, new spell, or new monster? If Mentzer's statement is 100% factual, it has to hold the record for the most orthodox, by the book campaign in history. Of course I'm sure he used the AD&D combat rules exactly as written.