Deedles, if it makes you feel better...Chas has said that as well. We have had the same discussions. I think at this age...most kids don't understand the concept of death fully.
We try to not watch t.v. shows or allow games in our house that are violent...but kids see it other places.
I think you handled it beautifully. I wouldn't worry about it. I think in this day as mom's we worry that our kid's might have issues if they say things like that....especially with everything that happens in today's world. If I think back to our childhood...we played cops and robbers and outlaws and sheriff... where we were shooting each other. Often arguing because the other person should be dead...because I shot them. I doubt my parents thought twice about it.