A summarization team measures ROUGE against reference summaries. A candidate receives a high score, but a reviewer finds an incorrect claim. Which conclusion is most appropriate?

1. A high ROUGE score guarantees every statement in the summary is supported by the source.
2. Text-overlap metrics can be useful signals but do not by themselves prove factual correctness; grounded or human quality checks are still needed.
3. Replacing ROUGE with a single token-count total guarantees that factual errors will disappear.
4. ROUGE measures only network latency, so it cannot say anything about generated text.