Protestant response? The guy who wrote that is a catholic priest.
Martin Luther was-a catholic priest too ?
Well then if he at all impugns the cherish view of the RCC then he must be a Prot. That is, unless he is a "true Catholic" as TradCaths defined themselves as (and they actually have a strong case for that, but not for the RCC being the NT church. For distinctive Catholic teachings are not manifest in the only wholly inspired substantive authoritative record of what the NT church believed (including how they understood the OT and gospels), which is Scripture, especially Acts thru Revelation.