We did, of course. St. John is a SAINT, not a Pope speaking Ex Catheda. Being a saint doesn't make one infallible.
Who said anything about infallibility?
St. John is a saint, and not just a saint, but a Doctor and Father of the Church; the greatest of the Eastern Fathers and second only to St. Augustine among all the Doctors of the Church Fathers, east or west.
So why on earth should I question the Golden-Mouthed Doctor's stance on the Jews, especially as it's in accord with Our Lord Himself, St. Paul, St. John the Beloved, and the overwhelming consensus of popes and saints and doctors across 19 centuries of Catholic history? Why should I take Abe Foxman's perspective on this subject over his? Why should anybody?
Why do you?