I foil at 165 and add 1/2 stick of unsalted butter cut lengthwise before closing. When you added liquid, you basically steamed the butt. If you injected the butt, you would not have had a situation where you felt you needed to add liquid. I would highly recommend following a Pro that has won multiple awards in this area
I basically follow this method with some added changes and turns out great every time.
http://virtualweberbullet.com/pork4.html
Good luck,
