Which of the following is NOT a likely cause for a motorman to report a defect?

Minor cosmetic damage is considered not a likely cause for a motorman to report a defect because it typically does not affect the operational capability or safety of the train. Cosmetic issues, such as scratches or small dents in the exterior of the train, do not usually interfere with the essential functions of the equipment or pose immediate risks to safety.

In contrast, visible wear and tear on equipment, unusual sounds during operation, and inconsistent performance of car functions are all significant indicators that may suggest underlying mechanical or operational issues that could potentially compromise safety or efficiency. Therefore, these factors would likely lead a motorman to report a defect to ensure that any necessary maintenance or inspections can be conducted promptly.