Preserve the different observations
A container-wide duration, a stream's timing and the last usable programme moment can differ in meaning. Write each with its source and units before comparing them. Do not replace missing values with zero or assume a summary field is a direct stopwatch observation.
Choose the actual owned file revision and inspect its required streams. An alternate audio track or a held final picture can affect what the audience experiences. A rounded duration display may also be too coarse for the investigation.
FFprobe can expose container, stream and frame information. Use the relevant view and label its scope; the tool's printed number does not decide whether a closing sentence was supposed to exist.
Review the endpoint itself
Inspect the final meaningful passage, the intended tail and any error near the end. Compare against a production record or trusted source copy where available. If a lecture should contain a final answer that is absent, the editorial issue remains even if its stored duration is internally consistent.
Conversely, a short difference between metadata displays does not automatically establish lost content. Compare with sufficient precision and preserve the explanation of how each tool obtained its value.
Make any recovery or remux candidate separately, then review the endpoint again. The acceptance note should connect the output duration, last reviewed content and required tracks. This is more useful than saying the numbers now match while the programme ending remains unexamined.
Questions answered
Does a duration mismatch always mean frames are missing?
No. Establish what each reported value describes.
Can matching duration numbers replace an ending review?
No. The required final content needs its own check.
Sources & further reading
Official references for the subjects discussed. Service terms and device software can change.