Without knowing more information this sound like one of two problems.

1. Your video card got too hot and didn't render for a moment
2. The frame buffer for playback saturated and froze.

There is also a possible anomaly that your control signal flickered the playback state and Cat interpreted as a change of play mode to pause.

Have you seen this again? If so, can you describe what exactly happened. Also, can you define the hardware and signal path.