They'll probably give you a good reference. They want to be the good guys on paper. However, if you are asked to give a reference for them, I understand that

They'll probably give you a good reference. They want to be the good guys on paper. However, if you are asked to give a reference for them, I understand that it's illegal to give negative criticism for an ex-employee review. I usually say something like, "It's not legal for me to comment negatively about XXXXX. Understand? Bye?".