I like Omid, but the point I WILL make is that if you leave Clementine behind, a walker breaks in and she saves Omid by killing it. It seems really stupid to me that, if you TAKE Clementine, that just doesn't happen. The only explanation for this I'll accept is that later in ep 5 we find out the walkie talkie man let that zombie in to try to take her out.
So, yes, if you brought Clem with you, I think he should have died. And Christa should never forgive you for that.