The paper work has nothing to do with you. Don't fill it out.

He's just using you. People do this if they know they can get away with it. If he can't return a phone call, you can't fill out his paperwork for him.
Don't let him take advantage of your kindness even when you guys are split up.

Don't be hatefull just tell him its not your information or business and that you can't fill it out and give the papers back to him and stop talking to him.