Generally, the journalist does not owe you to follow you instructions, just as any other person. They might do it if they want to be nice, or cooperative with you, or like you, or owe you loyalty somehow, or count on repeated cooperation in the future. So I guess the question one needs to ask oneself is - does this particular person, acting as a journalist, owes me any loyalty or has a special reason to feel they have to be nice to me? If not, expect nothing - anything you say can and will be used however they see fit, just as in any other conversation with a total stranger. Just because somebody calls themselves "journalist" doesn't make them any different.
