That's just being nice. Study moar law.
1) If he helped Kallen from being found out, that would be contradictory. He just didn't say anything.
2)He never said she had a right to be a terrorist. He even stated out his goal was to show her a better way. But she's a blockhead, so that was a no-go.>BAWWWWWWWWWWWWWs about not killing civilians then helps out the people who were just minutes earlier murdering civilians.
Once again, he doesn't aid them in doing so. He doesn't help Britanians murder civilians, he actually fights to stop casualties on both sides and has been shown to be effective in this. What he can't forgive most of all is the instigator, the one who decides to make moves which cause other people to kill in return, ala Zero.
I understand if his way of thinking is too complex for you to grasp. It's a common thing among young people nowadays to avoid thinking outside the box.