Corporate Manslaughter and Corporate Homicide Bill

It may give clarity to other Members of the Committee, but I am a bit stupid and it does not give complete clarity to me. What is the justification for excluding all those items in Clause 2(1)(c) in relation to public authorities? All afternoon, I have been trying to get at why the Government are restricting the liability of public authorities under the Bill to Clause 2(1)(a), in other words to their employees, and Clause 2(1)(b) as occupiers of premises. What is wrong with making them liable in the circumstances of Clause 2(1)(c)? Can the Minister explain in the practical language that my noble friend Lord James uses when he gives examples?