You are not breaking the law by killing the deer if you are not hunting deer. The law regarding hunting with dogs states that there is no such thing as accidental hunting, which means hunting has to be intentional, otherwise it's not hunting, therefore, providing you are legally hunting within the law, ie, using the exemptions for rat and rabbit, which are only exemptions with permission. you are not hunting deer, so any deer killed by accident do not contravene the hunting with dogs act. The question is, are you then allowed to benefit from said accident, most probably not. Having said that a