At risk of derailment, how does a “typical brand new know-nothingNovus Ordo parishioner” know how or when to make all the responses of the TLM (and apparently with confidence, if he is doing it from the front row)?

No normal person would do such a thing. He likely was the king of his Novus Ordo church, ("In the house of a blind man the one eyed man is a king") and he thinks he also knows more than all the people in the Sanford Chapel. Likely the liberal prior encouraged him to get up there, so the pastor could sneak in a type of Dialogue Mass. He gets a missal reads the responses and does the postures he was told to do. If it was a normal American prior, that person would not be up there, he'd be in the back keeping quiet.