How does an "emergency" shutdown button get that dirty? That looks heavily used.
It got pushed once in 1955 by a supervisor who had to jump over the table to hit it, because the employee in charge of the panel was chatting on the phone with his wife.
It was hit too late though, and half the core melted down.
(That's particularly bad for breeder reactors, because it can cause a nuclear explosion.)
Ironically, the entire chain-of-events was precipitated by a different wrong button being pressed.
https://en.wikipedia.org/wiki/Scram#/media/File:NS_Savannah_...