You said it yourself when you asked the question "How could anyone in their right mind think that was an ok thing to do?"
Asleep JWs are not in their "right" mind they are in an indoctrinated mind and they will speak from the script of that indoctrination.
You could try asking him if he will miss hunting in the new world. Drawing attention to percieved negatives as if they are positves can get some people to think. For eg, you could say "wont it be great when there will be no more hunting or guns." If he can admit there will be at least one thing about the new world he won't like he may start thinking a bit deeper about other things. I found just reminding dubs there will be no cafe's and shops really pisses some JWs off and they don't like to think about a world with no retail therapy. Drawing attention to the negatives by describing them as postives can sometimes get people to think.