They detected a quiet period of slower transitions before the spontaneous drop to the middle state... this implies that "something" happens prior to the transition.
They were able to detect this "something", and even prevent the state change.
In my mind, that "something" represents a hidden state or something like it within the synthetic atom.
The trouble is there are some strong arguments against that idea, so quantum physicists tend to assume that such "somethings" just don't exist. Yes, that is very counter-intuitive, but that is one reason quantum physics is so weird.
They were able to detect this "something", and even prevent the state change.
In my mind, that "something" represents a hidden state or something like it within the synthetic atom.