I also found it odd that he would go to the 5th floor alone and that no one else on the tour knew what he was doing. And how did he even know how to get to the 5th floor? Floor 5 was not indicated on the elevator buttons so how did he get there? If it was really a restricted area then wouldn’t any entrance from the stairwell be locked?
I find it curious that someone from the tour company made it a point to tell them they could not go to the 5th floor. Why would any tour participant even think to do so or know it even existed since there was no 5th floor indicated in the elevator? It’s like they were setting a trap to lure some tourist to try it and then get taken as a hostage.