I didn't think it through for any kind of logical consistency -- it's pure snap judgment. I think my instinct when presented with this kind of ethical dilemma is treat my own qalys (well, qalsecs) as far less valuable than those of another person. Or possibly I'm just paying an emotional surcharge for actually taking the action of ending another person's life. There was some sense of "having enough time to do something of import (e.g., call loved ones)" in there too.