I would actually be one of the 51% if given this poll. This issue is more complicated than it appears at first, and Internet culture tends to obscure this for some reason (I don't think it's just this site, but a lot of bloggers).
The Bible says God created man in his present form. If I consider myself a Christian destined for eternal salvation, and there are a variety of cultural, personal, and rational reasons to make this leap of faith, then I cannot answer in reply to this question that God has no role in creating humans. In making such an answer I have unequivocally rejected God, and any hope of life after death.
On the other hand there are obviously compelling reasons to believe in evolution. This creates I believe a sort of duality in life which can be left either resolved or unresolved, but there are powerful forces moving in the direction of non-resolution just as there are powerful forces moving in the direction of resolution. Just because the issue is not resolved it does not necessarily mean, though perhaps it unfortunately frequently does, that the person has not grappled with these issues deeply. I think that I have, and the matter is still unresolved. This is possible when two absolutes, truth and life, clash with one another.
It is because of this duality that I think you see these responses, with only 15% taking the atheist position but 67% also not rejecting that position. Seen from this view the responses are perfectly understandable and no mystery at all.
Great post