This is an odd statement, given that Orthodox and Catholics have many, many teachings in common. Both differ much more from Protestantism than from each other, or so it seems to me. Perhaps he was referring to those few teachings on which we differ, but he made it sound like we are far more separated than I believe we are.
There is a book available called "Coming Home" which was edited by Fr. Peter Gilquist. It's the stories of over a dozen or so clergy from other Christian faiths who have come to embrace Orthodoxy. Available at www.conciliarpress.com.