See, you have made the same mistake in the use of "proven" that many people do. A Proof is a mathematical term which can't be applied to non-testable ideas. So since creationism is based on something that is impossible to measure, it cannot be proven. I hesitate to say that Evolution has been proven because I am not familiar with any mathematical studies of the evolutionary process. The theory of evolution however, has been tested and observations have been made that support the theory. So we do know for a fact that the evolutionary process occurs, but it hasn't been "proven" in the mathematical view. And, please if there is anyone more knowledgeable in this please correct me if I am wrong.
And a scientist believing in a creator does not mean that Creationism is valid. It makes sense that most scientists would be religious due to the fact that Christianity is indoctrinated into every facet of American life. Even I have a hard time saying that God doesn't exist because I've been told so long that he/she does exist and I have no way to prove or test that he/she doesn't. So I consider it a non-issue and move on.
My whole point however is that creationism belongs in the realm of theology and not science based strictly on that fact that it cannot be tested.