Interesting. The bolded does not include the need for a pope. The Catholic Faith teaches that the pope's stamp of approval is what makes an ecumenical council infallible.
The thing is, like so many other Catholics, this FSSP priest has the whole schism mindset due in large part to this false teaching as taught in LG 25. By confusing/replacing Pentecost with the the "New Pentecost" as JXXIII and JP2 called it, (which, as Fr. Hesse says, calling V2 the New Pentecost is blasphemous to even say) if anything, he is actually the one in schism with the true Church.
After Pentecost is when St. Peter and all the Apostles were individually infallible. God did this in order to establish and facilitate the beginnings of the Church throughout the entire world. Whatever each of the Apostles, individually dispersed as they were throughout the world, taught regarding faith or morals, by virtue of the descent of the Holy Ghost at Pentecost, were most certainly 1) each individually infallible, and on that account 2) whatever they taught regarding the faith, they would have all taught the exact same thing in unison, as such 3) no matter what they taught regarding the faith, they would have all been in agreement with each other and St. Peter - not to mention with all the future popes whenever they speak ex cathedra till the end of time. That's infallibility, that's how infallibility worked when the Church on earth was in it's infancy.
There was nothing added nor can there ever be anything added to the Deposit of Faith since the death of the last Apostle - so what need is there to have all the bishops infallible? The whole idea is actually preposterous when you stop to think about it.
Enter V2, the "New Pentecost". LG 25, like all things NO, changed the true doctrine of the Church into a false doctrine of the new church by taking the birth of the Church at Pentecost, and from that, spinning a new doctrine to fit the new birth of the new church. In this new Pentecost, the false doctrine of infallibility is not based on the teaching revealed truth, rather, it is based on the collegiality, i.e. the unison of the hierarchy all teaching the same (wrong) thing, re: LG 25. It's truly diabolical, albeit an integral ingredient for the NO to get the people to go NO.
People believe and accept(ed) this false NO doctrine to be a de fide teaching of the True Church, which explains why so many abandoned the true faith for the new faith of the Novus Ordo. Most people still believe this, which explains why 60 years later and in spite of all the devastation, so many people, like Fr. Bisig, still argue against the true faith in favor of the Novus Ordo.