Livestock farmers have had free access to shooting lions forever in more remote areas of Botswana (remote from DWNP posts at least) and up until fairly recently I think the act stated that you had to have made an effort to kill the predator to receive compensation, or at least that you were allowed to "have a go" after livestock predation ( I seem to remember three days after but maybe I imagined that bit). When I was in the Makgadikgadi I got the distinct impression that a lot more lions would have been killed by farmers if they hadn't have thought it would have been noticed by the researcher with the collars. The law allowed them to chase after livestock killers with pretty much anything except a snare or a dog. There was also a tacit agreement between the local DWNP officials and the community that leg hold traps were fine to use (as the wording of the act was specific to snare) and up until the first ban on hunting all lions killed were trapped and then shot. As soon as the ban came along the only anthropogenic mortality was due to poisoning. I presume in areas where the law has never really had much bite nothing has probably changed people are continuing to trap, shoot or poison as they seem fit, however in areas more closely policed such as around the Okavango I would think that people would feel it a legitimate possibility that they would actually get caught killing lions now and thus might take up the poison.