Evolution vs Creationism

Alex Tabarrok is missing something in his Theism vs Evolution posts. He claims that "Creationism follows rationally from Theism." That is, you are being perfectly rational believing in Creationism given that you believe in God. Here is his argument:

Suppose that you find a watch in the forest. If you know there is no watchmaker then the theory of evolution is a brilliant and compelling explanation for the presence of complexity without design. But suppose that you know a watchmaker exists then surely the simplest and most compelling explanation is that the watchmaker made the watch. Any other explanation, particularly one so improbable (see extension) as evolution would seem to be preposterous and beside the point.

But now suppose that you are out in the forest and you find fossils. You find evidence that species have been slowly changing over time and some have died out. Suppose you find DNA and learn how is it passed on. You find a probable mechanism for evolution. Is the rational explanation still that a Creator have must made all the different species at some definate point in time? Or is it more likely that while a Creator could still be an explanation of why life exists or how it became so complicated, perhaps it was through a process of evolution that she did the creating.

Defending his first post Tabarrok writes

Suppose that God came down from the heavens tomorrow in all his glory, throwing thunderbolts, raising the dead, turning water into wine, whatever it takes to convince everyone of his existence. If this were to occur I have no doubt that even Richard Dawkins, precisely because he is a rational scientist, would say 'hmmm, perhaps I wasn't quite right about all this evolution stuff.'

This is confirmation that he thinks of Evolution and the existence of God as mutally exclusive. No rationalist needs to feel compelled to change his opinion on evolution given evidence of God.