Absolutely, positively an incorrect statement. The entire manual, whether FOM/GOM in addition to the equivalent of the Boeing FCOM is FAA approved and as such, MUST be followed. In addition, many carriers have an approved Maneuvers & Procedures Manual, or similiar such document, which covers just about everything. Guess what, it's also FAA approved and MUST be adhered to. If you think there is lattitude to "free wheel" you are sadly mistaken. Again, I'm coming from a 14 CFR 121 background and from my experience, Part 135 doesn't vary much either.

Standarization of procedures is the main reason that air carriers have enjoyed the safety record that they have over the past several decades.

Fly by the Book Mates