Which of the following is NOT a consequence of human error?

The choice that indicates a consequence which is NOT typically associated with human error is mental stressor. While mental stress can certainly be a factor in various work environments, it is often considered a condition or a state of being rather than a direct consequence of human error itself.

Physical injury, operational delay, and cost increase are all tangible outcomes that arise directly from mistakes made by individuals during operations or processes. For instance, an oversight can result in a physical injury when safety protocols are not followed. Similarly, human error can lead to delays in operations when tasks are not executed properly, thus affecting timelines. Additionally, mistakes that lead to inefficiencies or damage can cause financial implications, resulting in increased costs for organizations.

Thus, while mental stress can be a byproduct of various work-related situations, it is not an immediate or direct consequence of a specific human error in the context of this question.