This is old news for some, but another Roman Catholic epologist deconverted a while back to agnosticism. I vaguely remember this guy. Quite a few years back I recall being on his discussion board, and being politely edited, along with a Roman Catholic apologist. He told us to take our disagreements elsewhere, if I recall.
On his way out the door of Romanism, he made an interesting point:
Catholics think people are so humble when they consider Catholicism, but so arrogant and proud when they question Catholicism. You really can't have it both ways. J. wants special treatment because Catholicism is "different." Don't you think everybody else thinks they're different too? The Orthodox? The 7th Day Adventists? The Mormons? Everybody makes a case that their position warrants some special deference for whatever reason. And when arguments fail, everybody falls back on the same "you're not being humble / teachable" excuse. It just doesn't fly. [source]