In some ways, I can see the "he killed someone to protect her", though I don't think it's nearly as sweet as everyone wants to make it. I mean, protection can be sweet, but it's not that sweet and fluffy.

And I do agree that it really had very little to do with Claire. Charlie might tell himself that he was trying to protect her and he might even believe that a little, but it was mostly to prove to himself that he could do things right, that he could make decisions for himself. It was very selfish of him to take away everyone else's options.