Collider wrote...
I save the refinery because:
a) That's what the mission was for in the first place
I don't think these people deserve to die just so Zaeed gets his revenge
c) The workers will stay dead, but Vido can be taken down later.
a)I think this may have been a case of Zaeed lying to you. I highly doubt he was hired to save the workers as apparently they were Vido's base of operations. In all likelihood, he told you what he thought you would believe and sympathize with. He might also have wanted to keep it secret so that you couldn't tip off Vido. I firmly believe that the mission had always been to kill vido.
b)I don't kill them so he can get revenge, I kill them because I think Vido should be taken down when the option presents itself.
c)You make a good point, but personally I feel that in the time it takes you to find and catch him again, it may no longer be convenient to do so as other things may have happened such as Reaper invasion or faction disputes. A good comparison situation would be Morinth. If you let her get away, Samara will have to track her down again, and in that time many people could be killed. The analogy fails in that the only death on the line is Morinth's, but it still displays the amount of lives that could be lost because of inaction.
That's my reasoning though, I don't actually expect you to agree with it. And to be on topic, Garrus shouldn't become a murderer because I don't need a murderer, I need a leader and a friend.