I do what I must to ensure that innocent lives are kept safe. Unfortunately there wasn't much time to formulate a plan to make it so all four of them made it out alive. [ He's just saying it how it is, sorry Emma! ]

I will do so from now on, depending on the situation at hand. But I'll try to use nonlethal methods a bit more.

[ meaning he can't ensure that he won't in serious circumstances outright kill the infected, but he's going to try. ]