He probably tried to loosen the noose (either before or after ejaculation... Wanna start a pool?), fell out of the chair he was standing on, hit his head on the way down, got wedged under the chair, bled like a stuck pig, and then either died from the head injury, from loss of blood, or from asphyxiation.
Or he was whacked by someone and they went to a lot of trouble to make it look like the above scenario.
Ain't life just grand?