Actually, the initial instruction for installing the vernacular only specified the readings--Epistle & Gospel, plus the "bidding prayers" (petitions) at the Offertory.
All the rest was to be in Latin, just as before.
From what I understand, Paul VI himself provided bad examples by having even much of the papl masses in the vernacular, I also recently read of when he had Sr. Lucia stand in front of him to recieve communion. I know Abp. Weakland and Abp. Bugnini designed the Novus Ordo, but it was Paul VI himself who sadly made the decsion to implement it.