There's a difference between killing and murder. Our society sanctions the former (as does most other societies) under certain circumstances. The question is where to draw that line.
When I climbed Rainier a couple years ago it was the day that the oldest climber/record holder was up there. I saw him on our descent above the Shrund with his son. The dude was in his 80's, trucking along, hard of hearing (his son kept yelling "Dad! DAD!!").