How can an uneducated but rational person differentiate between science and religion?

I recently found myself unable to respond to the statement "But the big bang theory is just another creation myth!" during a science vs. religion argument. I found it very difficult to explain the difference between the big bang theory and creation myths without going through a crash course in Newtonian and then Relativistic mechanics. This had me thinking of the following scenario: Consider a person who for various reasons never got a formal education beyond basic reading and writing. He/She doesn't know any science or math, and was never exposed to any scientific reasoning and experiments. She/He is however an open minded, level headed, and rational person (I've met more than one such person myself). How would such a person differentiate science from religion? As far as he/she is concerned science has the exact same structure as religion: A hard to understand scripture: Science treatises and journal papers. An ordained clergy with a high entry barrier: Doctors, professors, scientists, etc... Seemingly arbitrary injunctions against certain behaviors: "Don't smoke", "Don't pollute",.... Various metaphysical (from his/her perspective) claims about the world around us: The big bang, other galaxies, blackholes, quarks,... Organizations which control and oversee doctrine: The FDA, The NIH, The NFS,... From his/her perspective, all of these characteristics are no different than the way organized religion presents itself as being the source of truths about the world. In particular if such a person were to heed the advice of the Kalama Sutra: Do not go upon what has been acquired by repeated hearing (anussava), nor upon tradition (paramparā), nor upon rumor (itikirā), nor upon what is in a scripture (piṭaka-sampadāna) nor upon surmise (takka-hetu), nor upon an axiom (naya-hetu), nor upon specious reasoning (ākāra-parivitakka), nor upon a bias towards a notion that has been pondered over (diṭṭhi-nijjhān-akkh-antiyā), nor upon another's seeming ability (bhabba-rūpatāya), nor