I don't know if this is true but in older versions if you left the containment chamber before triggering the escape sequence, the entire facility would still have lights on. I don't know if this is still true as of recent versions.
Best way to check is to go NOCLIP and explore the site.
Re: Turning the lights back on
#11SCP:CB Administrator. 99% of my statements are my own and do not represent the official developers viewpoint.