The should be a pause button on your camera device:

Now version

It just keeps transmitting the last frame it saw to the other "participants". If someone says "hey, Steve, your video's frozen", you can click the unpause button and say "hm. go figure."

The soon version

You click pause and Al Technology keeps your head and face moving around just a bit to be plausible. Maybe you just sway back and forth a few centimeters so people can say to themselves "oh, he's not frozen".

When you click unpause, the Al Technology morphs the frozen frame into the current frame in the best (most 'realistic') way possible: If you've moved over three inches, then "unpause" causes your final frame to animate to match your "actual" position before transmitting actual video again.

tl;dr -- A way to turn off your camera without getting in "trouble".