I’m not sure that a council itself can be infallible or non-infallible. I think that only teachings or proclamations of dogma (perhaps cming from a council) can be infallible. Obviously the council was binding, meaning that we are all required to submit to the teachings and practices therein.
What I’m getting at is maybe you are having a hard time finding an answer because you are asking the wrong question. A council can determine matters of discipline (like the use of more Scripture in the liturgy, LG #35) which are binding, but for which the question of infallibility does not arise. AFAIK, the statements in the Vatican II documents are either of that nature, or relate to statements that were previously defined infallibly (and thus have no need ot being defined infallibly again, by definition), or are sort of “position statements” not requiring any specific action or dogmatic assent, like “One engages in the apostolate through the faith, hope, and charity which the Holy Spirit diffuses in all members of the Church.” (AA #3)
But I’m not an expert. I may be over-simplifying.
–Jen