Exactly. Unlike religion, scientific-method-based atheism is a passive system.
Should proof of god emerge, then the scientific-method-based atheist would be logically required to believe in him (if you can call that "belief in").
Granted the atheist would probably avoid the terminology "God" as it's so suggestive of the "other-worldly."
EDIT: This is a point I've made many times before, but there's a fundamental problem with the language here. The word "believe" is far too vague.
Religious belief is intangible - it's like your belief that your mother loves you. Or the belief that aggression is wicked.
Scientific belief is concrete - it's like believing that the apple you are holding is real. More complex concepts and mechanisms are built up on smaller proven units and bound together with logic. In many ways, the term "scientific belief" is more similar to "understanding" than belief.
In this way, scientific theories are almost like religious beliefs. The only difference is that scientific theories are extrapolations grounded in the concrete whereas religious beliefs are further intangible items grounded in other religious beliefs or not grounded in anything at all.