Not every discontinuity (CC error) will cause a problem in an ES. For example, if a TS packet was dropped in the middle of a video slice, Sentry wouldn’t notice this as long as it can still detect the ‘start code’ progression in the video stream. We do more exhaustive analysis of I-Frames, but a missing packet in a P or B picture slice might very well not cause a video problem for us (thus no reason code).