Beyond the Grave
First of all, professional wrestling has always told stories that blur the line between reality and fiction. These stories are the ones that make the greatest impact, and, sometimes, even teach us a lesson.
Second, William Moody loved the wrestling business. His other love was the mortuary business. The most memorable part of his career involved him carrying an urn which possessed some sort of power and escorting a dead man to the ring. He used the name Paul Bearer.
Third, heels need the audience to hate them. CM Punk, like several of the guys nowadays, can go back and forth seamlessly. This sometimes can make it hard for the audience to choose sides in match. Doing something like what he did Monday night gave the audience the position they needed to have passion in this match.
I am sure Moody was loving Monday's Raw as he watched from above. Even in death, he was an instrumental part of setting up a conflict for a WrestleMania main event. How many people can say that? I actually hope this continues through WrestleMania, with Punk holding the urn captive until then. With McMahon's magic, Moody can help Taker win at WrestleMania from beyond the grave.