Yes, that's very much the theory. As I mentioned, doesn't always happen in practice (the one case I know of, the airline systems may have been confused by "transit" in the USA, and therefore didn't validate the ESTA, or possibly a checkin agent bypassed the checks because the final destination matched the passsengers passport, and they ignored the "transit" requirements - said traveller applied for an ESTA during the flight, and therefore didn't experience any difficulties on arrival into the US).