The idea that Bush is a "science buff" is ridiculous. There might be acouple of areas where he goes: "Gee whiz, what won't they think of next." But that is it. Bush's old adversary had to win a Nobel Prize before he grudgingly accepted global warming.
Bush does not believe in the theory of evolution. "The court is still out," he says in his inimitable style. Someone who disbelieves in evolution has neither knowledge of biology and geology nor understanding of the scientific method. He does not understand that science changes constantly as new information comes in. Nor do observable facts, as opposed to blind faith, pay an expecially important part in his decision making.
The fact that a NUMBER turned out to be smaller than expected is about the easiest fact to understand. A chimp can understand two bananas are less than five. It is more reasonable to assume that Bush always wanted no additional stem cell lines, and the fact that there seemed to be enough gave him something to hang is hat on. So new facts did not sway his moral position.
Teddy Roosevelt was a real science buff. He read Scientific American every month. Can you even imagine...?