Who's to say there can't be a combination of factors? God used evolution as a means of experimenting to find out what things worked and what things didn't, but decided to spin a few wrinkles of his own into the mix as well?
Personally I think some sort of hybrid theory is probably closer to reality than either theory taken alone.
You are inventing a novel idea of God -- one that isn't all knowing and therefore one who has to experiment -- therefore there is some fabric of the universe that he does not control, but that he is constrained to test and obey.