Harry and Hermione owned a luxury riverside property on the Yarra River. They had purchased it as a shell of a stately home and, after many years of renovation, Hermione was finally happy with the result. They loved the French doors opening onto a sweep of lawn with a view of the river. The lawn ran down to a low retaining wall with a flat top, and there was a significant drop to the river below. When Harry and Hermione went on their annual holiday to the south of France, they left the house in the care of their nephew, Dudley. Dudley always enjoyed the yearly responsibilities of housesitter, since it allowed him to entertain in surroundings to which he could never otherwise aspire. During the month in which Harry and Hermione were away, the house was always full. The visitors were generally Dudley's university mates from the Engineering faculty - mainly males of around 20 years of age. One morning, after a particularly heavy night of drinking, one of Dudley's friends, Piers, woke early, i.e. earlier than everyone else - and decided to go for a swim. Still drunk, and without bothering to change out of his boxer shorts and tee-shirt, he hurtled down the slope and onto the top of the retaining wall. Staggering slightly, he stopped to catch his breath. He then leapt from the top of the wall, yelling 'yahoo' as he did so. His yell woke Dudley, who staggered from his bed. He found Piers floating face down in the water and leapt in to rescue him. Holding Piers by the chin and using the sidestroke, Dudley brought him to shore. This was not easy, since Piers was very large. Piers was not breathing, and Dudley, who had completed a first aid course, was successful in resuscitating him. However, Piers had sustained spinal injuries when he had hit a snag hidden by the murky waters of the Yarra. The injury had been exacerbated when Dudley had pulled him out of the water. Piers was paralysed from the neck down. He sued Harry and Hermione for failing to display a sign saying that it was not safe to dive into the water, and he also sued Dudley for exacerbating his injuries when he rescued him. Using a problem-solving format, analyse Piers' chances of success in a case in negligence.