Java – What does "TILT" mean in a comment?

I read Clean the code by Robert C. Martin and the phrase TILT inexplicably appears in some code examples. Example (by the way, in Java):

                ...
public String errorMessage () {
Switch (status) {
case ErrorCode.OK:
// TILT - should not come here.
Return "";
case ErrorCode.UNEXPECTED_ARGUMENT:
return "Unexpected argument";
case ErrorCode.MISSING_ARGUMENT:
Return "missing argument";
...
}
...

I appreciate from the context TILT denotes a state that is unreachable and is included only to satisfy the compiler (eg, in the above code). TILT appears in Fehlercode.OK Case, because there should be no error message when the status is OK), but I am not sure.

Does anyone know what? TILT stands for / means?