I don't know the answer to your question, but a RADAR key alone wouldn't be able to open a toilet cubicle, if it is locked from the inside.
The idea of the lock is that it locks the door. Many of them don't do, not properly, but that's only if the lock's defective. A red/white disc is intended to indicate whether or not the toilet is occupied, but, there again, I'm aware that they don't always give a correct indication.Lots of them will open if they're locked, so you're supposed to knock before using the key.
They have a disc on the outside which can be turned with a coin to unlock them when they're locked from the inside.
Of that I wasn't aware, but I'd never really thought about it.
Q.E.D. If the lock is activated, and it's working properly, a RADAR key wouldn't effect an entry.