Has anyone proposed a combination of these theories:
Pippin was indeed a rat and was intended to either continue, or re-establish the activities
the Mallers desired. So he knew there was someone else there in theory and he was supposed to be actively searching. Suddenly when Pippin was alone, a man/woman walks in holding a
silenced pistol so immediately Pippin knows who he was supposed to be looking for in the first place. The "It's You" could have been anyone in
the Tower even someone he had met before simply because they had just exposed themselves as the Rat.
just a thought that popped in my head listening to WND just now.