I know concord won't come after you for firing on an outlaw in hisec. But what if you managed to get their ship, and tried podding them?
Generally speaking, podding is never allowed in high sec space. The only exceptions to this are if you've declared war against the other person's player corp (can't war dec NPC corps, of course), or if you're in faction warfare. You can blow up the ship of the outlaw, but you can't pod him.