Final answer:
An intervening cause is not a required element to prove negligent liability but rather something a defendant might use to argue against causation. Negligence requires proving duty, breach, causation, and damages, as illustrated by a manufacturer held liable for selling a car model with a known brake defect.
Step-by-step explanation:
The subject question pertains to the required elements that need to be proved to establish negligent liability in a legal context. To establish negligence, the plaintiff must typically demonstrate the following elements: a duty to act, a breach of that duty, causation, and damages. Causation itself is further divided into two parts: the cause in fact (often termed actual cause) and proximate cause. An intervening cause is something that breaks the causal chain between the defendant's conduct and the end result, but it is typically not a required element that the plaintiff must prove; rather, it is something that a defendant might introduce to avoid liability.
In the Counter Example Situation 3 provided, the automobile manufacturer would be held liable for the injuries and deaths caused by the brake failures of one of its models because the necessary elements to establish negligence are present: the manufacturer had a duty to ensure the safety of the automobiles, it breached that duty by selling a model with known defects, that breach caused accidents (actual cause), and the accidents were a foreseeable result of that breach (proximate cause), leading to tangible damages in the form of injuries and deaths.