Yeah that's true but it's not really a problem if u teleport in a wall, because then you can just teleport down agan, that's how they solved it. I have been testing it and i think i understand a little more of how the admin script works.
You doesn't only have a teleport command they have much much more, like freeze, slay, disarm and more with that admin system u just point and does a command on the player or on the spot your watching on.
It's like if it's searching for a player or x,y and z cordinates, really smart if u ask me.
The admin script is named Point And Punish and is made for Eventscript, i am not sure if i am allowed to put links to other sites here so if u want the link to it i can send a PM.
It would be fun if it came to sourcemod, the admin system in eventscript is not so great and almost everythime u have to use your steamid.