Final answer:
The legal issue central to the argument between Lilly and the City of Scottsdale is whether the detour was the proximate cause of the damage to Lilly's car.
Step-by-step explanation:
The legal issue central to the argument between Lilly and the City of Scottsdale is whether the detour was the proximate cause of the damage to Lilly's car. Proximate cause refers to the legal concept of foreseeability and whether the harm caused by an action was reasonably foreseeable. In this case, Lilly is claiming that if it wasn't for the parade detour, she wouldn't have taken the unfamiliar route and wouldn't have been involved in the accident.
The City of Scottsdale is arguing that it cannot be held responsible for the damage as they determined the road closures for the safety of the parade participants and spectators.