Note that the police tech who came first haven't turned the lights on either. Perhaps he didn't know where the switches are. But a more likely explanation is that the camera that the cop was wearing is not very good in low light. Note that it kept sending the picture in color, though most security cameras switch to grayscale below a certain lighting threshold. Human eyes are better than many security cameras, and they are certainly better than this camera. Note that the picture outside the station - which is a city street with lights - is also unusably dark; but most people find that streetlights are adequate for walking around.
This means that while there wasn't enough light for the camera, there probably was just enough light for humans to walk around. The police tech may have been forced to wander around in darkness because he didn't know where the switches are, and the firefighter didn't need the overhead lights because he knew the facility well enough - especially if he told his kids to stay by the doors.
Occam's razor....
/johnny