How should answers to questions that have since been split be dealt with?

Question

I came across Ubuntu screenshot program, which started off as a couple questions mashed together. Although it has since been edited to only ask about screenshot programs, it originally asked for both these and applications for taking notes. As a result, answers have been provided which only answer one of those questions (either the kept one or about the notes) or both. As such, some of the answers' content now appears partially or completely off-topic with regards to the question although they once were not. (This, IMHO, is a great example of why we only allow one question per post.)

How can messy situations like this be best dealt with?

Answer 1

I don't know if there's some automated way but the task seems to need interaction anyway. The best might be to write a comment to each answer and write that the question has been reduced to one question now, that some parts of the answer is off-topic and provide links to the other parts of the original question so that the authors may move their answer there.

If this is something that needs to been often it might make sense to put together a good pro-forma comment.