John and Bill had consumed beer and smoked marijuana before going with Gosling for the evening to a bar, where they all consumed a considerable amount of alcohol. They were drunk when they left and got into Bill's car so that he could drive them home. A single-car accident caused by his impairment occurred in which Bill rolled the car and Gosling was seriously injured. Gosling sued Bill for negligence.

Question: Indicate what arguments can be raised in Bill's defence and what factors the courts will take into consideration in determining liability.