Actually, it works like this, for example…
On channel 5-1, recording starts at 9AM, and ends at 10AM, and no recording on that channel just ended at 9AM.
If you start watching channel 5-1 (Live TV) before 9AM, then you can continue to watch that channel past 10AM, when the recording ends.
If you start watching channel 5-1 (Live TV) between 9AM, and 10AM, then the Live TV stream will end at 10AM.