What is the test for negligence when a plaintiff falls off a ladder while assisting with the installation of drywall?

In the case of James v. Schmidt (1993) O.J. No. 2287 the plaintiff went to the home of the defendant to help him install some drywall. The defendant was standing on a stool holding a piece of sheetrock and the plaintiff was holding the other end. As the plaintiff climbed a stepladder to fit the sheetrock in place he lost his balance and fell to the floor. The claim of the plaintiff was dismissed, the court held that it was the negligence of the plaintiff in losing his balance and falling off the ladder that resulted in his injury. It was held that the defendant had examined the area before the work began and took reasonable care to ensure that the plaintiff was safe.