When I was the Chief Pilot of a Part 61 Flight School I interviewed CFI's all the time due to the regionals hireing (then they were called "Commuters"). I took a not so new CFI on a short check out flight in a 172. He proceded to teach me how to roll the 172 correctly. (I never asked) I just looked at him during the first roll. I told him we did not do that at our school and he said "No, it is real easy just do it this way..." He did not get the job. Another CFI I interviewed told me he did not like to talk, he woud just show the student what to do. I asked another CFI to teach me about "what makes an airplane fly". He spent thirty minutes telling me about two air molucules named "Moe and Joe" and at the end of the half hour I had no idea what he was talking about.