So the Bible is true because the Bible says it is true, and Libby should have remembered that. Oh, and the evidence backs it up. Why not just say that the Earth is young because that is what the evidence says? I think Dr. Purdom is revealing more than she may want to with this statement.
I read the Drs. position a bit differently.
I read him as saying the following:
That the Bible is true is a given. So what the Bible says is right. The evidence, when interpreted correctly also supports the Bible, but it is possible to become confused.
The process for getting unconfused, according to Ham and Purdom, is to read the Bible, and then, only for those who understand science at all, to get a Creation Scientist to explain what the science really says. Other, secular sources may be wrong or lying.
Perhaps the above seems little different from your take. But it does not require that the Dr. Dino and Dr. Purdom are lying or trying to isolate. They are trying to innoculate, but they honestly do see their vision of the Bible as the absolute truth.
I really don't see anything new about the strategy.
Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)
The apathy of the people is enough to make every statue leap from its pedestal and hasten the resurrection of the dead. William Lloyd Garrison