Once you touch it, you are just as liable as the other person. Having a license doesn't mean you're obligated to do the work. Just say NO! If money is more important and you decide to work on it, make sure everything meets code. And I mean EVERYTHING! Otherwise, see you in court!
I catch myself 'inspecting' a few of these, to the point of 'advising' the owners. Probably not good, being a contractor fairly displaced from any sort of 'sovern immunity' I have directed a few individulas to the DIYer forums....they're gonna do it anyway...