Just proves the old adage - Written agreement avoids problems, even between people of integrity or good intentions.
Not to say that some are not out to miss-represent or deceive but there are times where I really want dear wife to "put that in writing" and she probably wants the same when she asks me about when I'll get "a round tuit".
Especially useful when dealing with folks of less sterling reputation, those are often best avoided. Generally does not work out well dealing with those folks.