ThatZenoGuy
Residential Zealous Evolved Nano Organism
I remember finishing Vault 13 as a stupid character, and pumping the gas to Navarro so I could kill Schreber (I had tagged Repair and actually managed to get it high enough to get the car), but even after I did, when I returned to V13 I got to see the massacre. But I had Goris with me the whole time, and he never gave me the "pack in danger" routine.
I think there are thwoconditions to be met:
1. Dr Schreber must be dead within two weeks of getting the reward from Gruthar, and
2. You must never return to Vault 13 after those two weeks have passed.
Nope.
Just kill the Dr before you meet the deathclaws, and they survive.