How do you know the app is not using a side channel to exfiltrate data through the normal mechanism of operation? Zoom - I expect it to require significant amou

How do you know the app is not using a side channel to exfiltrate data through the normal mechanism of operation? Zoom - I expect it to require significant amount of bandwidth to operate. How am I to know that if remote call X fails it will not just route data through the video path?