I think I noticed that and found it off putting, but I didn’t take it as an “anti-Catholic rant,” just a bit of culturally inculcated ignorance no one’s corrected. Some time back Mark Levin had a caller who mentioned, as an aside, how before Columbus everyone thought the Earth was flat. Now, it’s a big myth that Columbus discovered the Earth was round. Educated people in the West knew that the Earth was round since the time of the ancient Greeks. The Medieval Ptolemaic cosmology was based around the fact! And yet this caller simply assumed that and Mark didn’t correct him. But it’s nothing more than widespread ignorance in our culture.
There’s a great book on that by Jeffrey Burton Russell called, The Myth of the Flat Earth. Here’s a summary by Russell: http://www.veritas-ucsb.org/library/russell/FlatEarth.html