This is highly doubtful. The reason Fawkes should be extermined is that he's a total jerk in the ending. "I could do this and survive because I'm immune to radiations, but you're the hero, I don't want to steal your thunder, so go die gallantly in the nukage."
Hah svcks for you. He never reufsed to offer to grab the GECK for me. Actually, I asked Charon to do it, which he went to do, then asked Fawkes, and Fawkes refused.