A survey that questions whether scientists believe in God might be tipped a little toward inaccuracy. They might not have had the time to consider in depth whether God is real, but honesty, which is probably common among scientists, might cause them to say no because it's more honest than yes seeing that they give no consideration to a diety.
I have heard of believing atheists. They can't believe everything happened without design but they give no consideration to the possibility that God is aware and they don't care what god thinks of them.