One small distinction:  these weren't the king's deer, they were all of ours.  This wasn't a case of subsistence hunting.  Rather, just 3 idiots driving around looking to poach deer.  It's a pretty simple concept; play by the rules the rest of us follow or run the risk of paying the penalty.  Your "stealing the kid's rifles" claim is laughable.  He used the rifles to commit a crime.  One of the penalties for using weapons to commit crimes is loss of the weapon.  In simpler words for you, this was not a civil forfeiture.