This is the door to the garage, and you can see it's not far from that desk area where those guy were milling around. You can even hear the reporter say it's the door to the parking area.
So, that means all these guys came storming through that door, with Oswald and Ruby in toe, Oswald being carried in critical condition, and Ruby being wrestled in.
So, how is it possible that just 7 seconds after the above pandemonium- 7 seconds- it had reverted to this?
7 seconds, for Christ's sake. That is obviously not just 7 seconds after the scene above.