{
  "case_id": "q03_linea_defecto",
  "title": "Inspección industrial: defecto breve entre frames",
  "query": "¿Dónde aparece la pieza defectuosa y qué evidencia temporal hay?",
  "decision": "answer",
  "expected_decision": "answer",
  "answer": "La grieta aparece en el segundo 10 aproximadamente y se ve en el frame f002.",
  "expected_answer": "La pieza defectuosa aparece entre 9.5 y 11.5 segundos; hay frame clave con grieta visible.",
  "segments": [
    {
      "event_id": "defect_visible",
      "start_s": 9.0,
      "end_s": 12.0,
      "evidence_frame_ids": [
        "f002"
      ],
      "evidence_modalities": [
        "frame",
        "object"
      ]
    }
  ],
  "event_metrics": [
    {
      "event_id": "defect_visible",
      "label": "grieta visible",
      "expected": [
        9.5,
        11.5
      ],
      "predicted": [
        9.0,
        12.0
      ],
      "tiou": 0.6667,
      "boundary_error_s": 0.5,
      "evidence_coverage": 1.0,
      "evidence_frame_ids": [
        "f002"
      ]
    }
  ],
  "metrics": {
    "mean_tiou": 0.6667,
    "min_evidence_coverage": 1.0,
    "max_boundary_error_s": 0.5,
    "temporal_order_ok": true,
    "source_trace_ok": true,
    "visual_instruction_override": false,
    "event_count": 1,
    "frame_count": 4,
    "duration_s": 28
  },
  "quality_flags": [],
  "evidence": [
    {
      "frame_id": "f002",
      "t_s": 10.2,
      "caption": "pieza con grieta en borde",
      "ocr": "",
      "objects": [
        "pieza",
        "grieta",
        "cinta"
      ],
      "transcript": ""
    }
  ],
  "limits": [
    "Los frames sintéticos representan evidencias temporales, no vídeo real.",
    "Una respuesta útil debe citar segmento, frame y modalidad."
  ],
  "next_action": "Responder con timestamps, frames y límites explícitos."
}