Can someone change their name to become admin?

Say for example, my ingame name was John, and I was an admin. In the permissions if John was set to be in the group admin, could someone that wasn't actually John rename their player to John to become and admin? Should I change the user in my permissions to my user id?

 

Hi,

I have tested this and you cannot take another name that is in use.
Using SteamID in permissions.cfg file is not possible, i wish it was possible though...

I had this tested in Alpha 13, but i doubt they have changed this in Alpha 14