Deal with the deathclaw

In Navarro, there is Xarn, an intellegent Deathclaw that the doctor wants dead. You can either


 * Spare him and let him escape (The pass key for this door can be found in the doctor's desk nearby)
 * Kill him
 * Or have him ally with you when you slaughter every single person on that floor in Navarro (it helps too whan you have K-9)