How to quit a QuickTime screen recording?
To stop a QuickTime screen recording, find the recording bar and click the Stop button. If you're unable to find it, hit the Esc key and then click the Stop button. However, in case the video application is non-responsive, you'll need to force quit it. To do that, click the Apple menu and choose Force Quit from the drop-down menu. Click QuickTime Player from the list and then click the Force Quit button.