If you set the hook.is_active to false, it will always be turned off, it should be:
hook.is_active = value
Thanks for letting me know. I'm busy at the Blender conference now but I'm taking note of this issue. 🙂
Just fixed the video, I'm reuploading it right now. There are some small visual differences as I upgraded to pop os 19.10 and they removed the slim themes. But hopefully it's not confusing, I tried to reproduce the original screen and lines of code for the fix.