Whilst I agree with you about the location of the cull being insensitive I would question the weapon used. The slaughterman does state that he is licensed to kill animals and so he is not just some numpty brought it off the street.
Also, having been on a Police firearms unit for a while I know the type of cartridge that would have been used. It is not a standard shotgun cartridge with lots of pellets inside, it is a 1 ounce rifled slug, a solid lump of lead that will stop an elephant. Using it turns the shotgun into a section 1 Firearm and only a registered user can have them, it does give the gun a hell of a kick though!