When is expert testimony not required in proving negligence?

Expert testimony is not required in proving negligence when the negligence is apparent to laypersons because such cases involve situations where the average person can easily understand the nature of the conduct and its unreasonable nature without the need for specialized knowledge. In these circumstances, the facts of the case themselves are straightforward and can be comprehended by individuals who do not have formal training in a specific field, making it unnecessary to have an expert explain the standard of care or the breach thereof.

In contrast, the other options present situations that do not inherently negate the need for expert testimony. Minor injuries might still require expert insights into standards of care or causation, especially if the nature of the negligence is nuanced. Similarly, the involvement of multiple defendants does not automatically simplify the case to a degree that expert testimony would become irrelevant. Additionally, while an admission of negligence may relieve the plaintiff from needing to prove that element of the case, the plaintiff still might need expert testimony for other aspects, such as damages or causation. Thus, the presence of clear negligence, understandable by a layperson, is the key factor that negates the need for expert testimony in those instances.