Right now he wouldn't believe it because Chariot's too nice to be evil. Depending on whether or not he really remembers what being a storm rider meant, he would probably just... take it in stride -- just because certain groups are "evil" doesn't mean every group is, and not going along with the cops is obviously a bad standard of judgment for such things.

If Chariot could share any one of the memories he's gotten so far, to help Spitfire understand "Dino" what would he pick?