And yet he said he was going out to 'shoot rabbits' on the eve of the murders!
So far as we can gather,he didn't shoot any. I just think he stepped out mid-argument that was happening around the table,for a breather before leaving and had no intention of shooting anything but felt less awkward leaving the family by using his excuse of hearing rabbits. He may well have heard them,but I would doubt very much,as I said,it was an excuse to get away from the heated debate before leaving. It's embarrassing standing there when others are intense in conversation so he made his excuses,as you would,to get out of that situation.