A group of seven-year-olds were taken on a school excursion to the zoo. Following lunch one of the teachers, Mr Philpott, allowed them to wander around in pairs and view the animals. He had previously taken them around the cages and had spoken to them about the dangerous characteristics of many of the animals. 

Simon and his friend were feeding an orangutan peanuts. The distance from the safety fence to the cage bars was too far for the orangutan to reach any visitor.

Simon had either fallen over the safety fence or climbed over the fence. He probably climbed over the fence to reach a bag of peanuts which he had dropped. The orangutan grabbed Simon, pinned him against the bars and injured his face and upper body.

Fully explain Simon's chances of pursuing a claim in negligence only.