(2.1) Except as otherwise provided in paragraph (2.2), an actor is presumed to have a reasonable belief that deadly force is immediately necessary to protect himself against death, serious bodily injury, kidnapping or sexual intercourse compelled by force or threat if both of the following conditions exist:
(i) The person against whom the force is used is in the process of unlawfully and forcefully entering, or has unlawfully and forcefully entered and is present within, a dwelling, residence or occupied vehicle; or the person against whom the force is used is or is attempting to unlawfully and forcefully remove another against that other's will from the dwelling, residence or occupied vehicle.
Probably enacted because of carjackings.
You neglected to post the second condition:
(ii) The actor knows or has reason to believe that the unlawful and forceful entry or act is occurring or has occurred.
Now this makes perfect sense for the PA residents.
Thanks for that....