Yes, Bishop Barron called James Martin a winsome guide. That is wrong. James Martin has clearly left the Catholic Church and is in open heretical beliefs regardless of what current positions he currently holds.
Bishop Barron should recall that to be winsome, there is a freshness or ingenuity required. Sin is never new nor fresh but the oldest and most boring thing alive.
Does it mean that someone who is wrong in one area cannot be right in another? No, Mr. Martin could be right in one area if he is wrong in another. Hence, this website will not remove previous posts promoting material on Vatican II created by Bishop Barron even know he is wrong in this matter.
Yet, can someone be a winsome guide for prayer if they have left the Church. Perhaps, but I doubt it if they have left in good conscience. It is one thing to say that someone who has left the Church in some sort of confusion has a personal prayer life that is of great value and it is another to say that this person should be a guide to prayer for others.
As I have said before, Martin Luther for example kept the belief in several Marian dogmas. He was wrong in a lot but not everything. As a result, if someone mentions Bishop Barron’s treatment of Vatican II it is not a valid argument to say that he is wrong about something else which is unrelated to prove that we should not listen to him at all.
There can be a link as there was for Mr. Martin where being wrong in one area makes him unsuitable as a guide for prayer, but Bishop Barron’s incorrect recommendation of Fr. Martin does not make his statements about Vatican II incorrect.