What if they merely put the ID away? What if they have all access with an Assistant ID? What about meta, when people will respond to demotions as "hey let's give him any job BUT assistant". What if they rename the ID to "Demoted"?

There are so many things that can go wrong with this in a live test. Your check depends on whether the ID has the title "Assistant" or not, also whether the target is wearing his ID.