I had a long "discussion" a while back with one of the more adamant creationists around here about what the "windows of heaven" (aka "floodgates of the heavens") referred to if not actual holes in something solid. She was--she had to be--comfortable with that phrase being a metaphor, offering a half dozen possible interpretations, but insisted that the creation account had to be taken literally. That's when I gave up on expecting any consistency in their arguments.
I don't expect a lot of consistency in creationist beliefs. Each creationist appears to have his/her own version of creation, which only partially matches the Bible, and their so-called "refutations" of science are all over the map, as well. Adamant creationists do not, in my experience, function within a logical framework.
It's kind of sad, in a way. I think the insistence on believing in a literal interpretation of the Bible harms the Christian faith. Kids raised in a tradition of rigid literal belief but who are also logical, intelligent, and curious about the natural world can very easily decide to throw away their faith when they see that the physical world doesn't conform to the Bible. I recently read about someone who did just that... became an atheist because his Christian parents taught him that science and faith are incompatible.