I've never been in a life and death situation, and hope i never will. But notice how when we turn to these extreme situations, we reach for the definition of terms, we find conclusions awkard and ambiguous. Personally, I think this is because discussion around such examples don't reflect what we face in day to day life. Any exploration would simply be out of intelectual entertainment.
The guys signature on the other hand, can be argued against on much simpler grounds. It varies from person to person, so it would be worse for some better for others. So its question one would respond to on a personal basis. It not somthing that has a real yes or no answer, as it depends on specifics.