And he will not necessarily be torn up about it later on, as we also saw on the show.
Oh glorious canon, you baffle me at times. It's so strange: a guy who gets mad at someone for making a joke about a dead guy (I remember that from the Pilot)--but is pretty apathetic about his own involvement in someone's death. Maybe it's just me, but I thought he would be more sensitive than that. Ah well. Guess that was some bias right there.
Stepping outside for a minute--it could also be that it being a family show, showing remorse would make the events somehow more dark than we're being led to take them. In the most extreme example mentioned above-- the lady shrinks. She _shrinks_. Remorse over that would be kind of hard to take seriously...well at least for me.
*shrug*
The nature of the show I think is key in considering why...
we never saw any indication in the show of a rage that would lead Clark to kill just for the sake of killing.
Or to parraphrase "a rage that would strip Clark of all rationality."
I *don't* hold this as an absolute either (that he would go murderously crazy if something horrible happened). All I'm saying is that I'm okay with either way, as long as I'm led carefully he'll still be "Clark" to me.
