I... guess both Admiral and Kiso both happened to forget to put their nameplate on the board?
It might have made sense if there was a timer in the system, so that Kiso falling asleep screwed with the system (it would show she was scheduled to already be out), but if it's a system where people manually "reserve" "docks" by placing their nameplate on the board, then the only reasons it wouldn't be there is either because she forgot to place her nameplate, or someone else came by and stole it as a prank. Admiral also should have placed his name before he entered, so again, either forgetting or someone stole it afterwards. Neither possibility has been stated, here, but the latter explanation would demand seeing some in-story explanation.
IN DOCKIN DOCKWell, there were no nameplates on the board at the time -kuma.--THAT'S WRONG!
It wasn't like that!*WHAM!*Wrong?!
Then she left the plates off so someone could come in for the thrill of being discovered?!IN DOCK*WHAM!*So, then why'd you even enter at that time...?Hunh?... But that means in the first place, anyone could come in--When did she become such an advanced student?!IN DOCKShould I freshen up -kuma?That makes it sound like I was happy I ran into Admiral...!