Exactly. The author needs to have a Trail-of-blood type explanation, or else he's confronted with the strange task of accusing the entire first centuries of the Church to be heterodox.
There are Protestants who admit their church is an innovation and like it that way. At least they are honest. Those Protestants tend to consider the orthodox past of the church (small o in orthodox) as anachronistic and that they are ‘evolving’ with the times to reflect modern values like female clergy and pro homosexual unions.I don’t agree with them but they are honest. They are not creating a DaVinci code conspiracy dating back 1,800 years.