Catholic teaching is indeed that non-Catholics are our brothers. If the author had made the effort to refer to the teachings of the Church contained in The Catechism of the Catholic Church he would have found the following:

#838 - "The Church knows that she is joined in many ways to the baptized who are honored by the name of Christian, but do not profess the Catholic faith in its entirety or have not preserved unity or communion under the successor of Peter." Those "who believe in Christ and have been properly baptized are put in a certain, although imperfect, communion with the Catholic Church." With the Orthodox Churches, this communion is so profound "that it lacks little to attain the fullness that would permit a common celebration of the Lord's Eucharist."

The author also uses a statement about Mary Immaculate to imply that Catholics are not "contending for the faith once delivered unto the saints!" The Church's teachings on Mary can not be summarized in this one statement made by the author; but again, we can look to the Catechism of the Catholic Church which states the following:

#480 - Jesus Christ is true God and true man, in the unity of his divine person; for this reason he is the one and only mediator between God and men.