You can just state that what Robinson 2018 changes and, if there is precedent, state what case. If not you can just use caparo. If its a 30 marker use caparo to establish why a duty was found. A02 would just be applying it to the scenario and yes you would use the cases studied if it is similiar. But if there is a slight difference then caparo may need to be used otherwise, when concerning evaluation points for a03, because a material difference would mean that the case would be distinguished from past precedent.