First off have you ever watched a hunting show? When they scream and yell for "nailing" that buck that they hit too far back and have to wait 24 hours before tracking.
This was a heck of a lot more ethical than many of the shows that a lot of people here rave about.
The guy was a competitive javelin thrower and he has many videos showing him practicing with the spear, making that shot over and over again. I saw that this is a lot more ethical than many hunters out there, you know the guys, the ones who pull the rifle out on the friday before the hunt, realize that they do not know where their ammo is, go grabs a box of whatever is in stock and refuse to shoot it to sight it in because "it was good last year and I don't want to spook the deer".
If you can hit your target every single time what does it matter what you are using, a massive spear tip to the vitals is a lot more ethical than many spray and pray guys out there.