In the interview, Laurie claims that she isn't in love with The Governor, that has nothing to do with the reason she didn't kill him. She knows that he is a bad man, however, she still holds reservations about taking a human life, any human life regardless of how bad it is. She knows that Phillip isn't the perfect saint that he hopes people will think he is, she has seen some pretty gruesome things that he has done and is shocked and appalled by many of them, but in a time when so few humans remain, sparing even one of them could be detrimental to rebuilding society.
Holden says that Andrea is staying in Woodbury out of loyalty and to help protect the innocent people that live in Woodbury as there are a lot of them that likely wouldn't survive without someone like her to take over when the walkers come storming through their gates. Holden also allows that during the rest of the season, Andrea will be trying to find the most humane way of dealing with things that doesn't involve killing humans. She wants to do things in a peaceful way like Dale did with Randall in season two.
Hopefully, this doesn't mean that the action and drama will end as peaceful and humane aren't always good qualities in a post apocalyptic world full of zombies trying to eat you alive.