Nothing in this Act shall be construed as affecting any enactment or any rule of law relating to -

(a) self-defence, the defence of others or the defence of property,

(b) any liability imposed on an occupier as a member of a particular class of persons including the following classes of persons:

(i) persons by virtue of a contract for the hire of, or for the carriage for reward of persons or property in, any vessel, vehicle, train, aircraft or other means of transport;

(ii) persons by virtue of a contract of bailment; and

(iii) employers in respect of their duties towards their employees, or

(c) any liability imposed on an occupier for a tort committed by another person in circumstances where the duty imposed on the occupier is of such a nature that its performance may not be delegated to another person.