You don't live in the country do you? :D They don't just hang about waving a flag saying shoot me.
And in the environment JB lived in you can be an animal lover and still kill "vermin" its part of life. I expect that to be part of "farming" life there was a lot of pressure for him to join the hunting/shooting/fishing set , you would be considered a woos if you didn't
There are woods near my house. Right now everything is covered in ice but otherwise deer and rabbits come to eat the plants in my yard. They come in all out yards but mine has more stuff to eat than most-we have a lot of different shrubs and bushes including some that have eaten to the ground in the past so I had to replace. It is not lawful to kill them to protect my plants nor do I believe in killing animals- like they said of Jeremy. Killing one or 2 would accomplish nothing anyway since I have no hope of killing them all and that is what would be necessary to prevent any rabbits or deer from coming to my property from the woods. The only thing that can be done is to run out and scare them away if they are noticed. They run away in a flash.
But if I did decide I wanted to try to kill them all and ignore the law then my family and neighbors would be aware of it because it would be my habit to try to kill them. If after all this time I suddenly decided to kill animals despite my past opposition then people will wonder what changed.
How interesting that Jeremy's alleged change came at such an odd time of day, when it would be unlikely for him to even notice the rabbits, for the gun to just happen to be missing the moderator and scope, loading it in front of Sheila, leaving it out... all right before the murders.