The thing is though scientists have huge egos so if a scientist comes up with a theory there will always be other scientists who will peer review his/her work and would critique it heavily if wrong - so science is to a large degree self-policing
Interestingly the same happens with theology. It, too, is self-correcting, over a loooong period of time. It used to be faster, in it's early days. Then again science, in the form which we have it today, is also in it's infancy LT, of the "some days I can't resist..." class