The explanation given there is sound when it is applied the veracity of historical written records that don't attempt to support the supernatural. It's just about measuring what the more reliable evidence is. Did so and so say such and such to this person and so 500 years ago? Best written records say so, and there are different pieces of records from different people who say so and so we deem it good enough to say it's accurate. That's a totally different ball game than trying to discredit contemporary physical evidence.
http://www.newadvent.org/cathen/04503a.htm