Skill-based errors, rule-based errors and knowledge-based mistakes are useful human-factors categories, but a clip does not reveal a person's reasoning. Video can show observable actions, timing and context. An operator discussion and process review are needed before deciding whether the cause was a slip, a misunderstood rule or missing knowledge. Use the classification to select a response, not to infer intent or assign blame automatically. Layout, instructions, tooling and training may each need attention.