The quote is actually a great way to phrase in simple terms an important property of quantum mechanics. It is called "unitarity" or equivalently "time evolution

The quote is actually a great way to phrase in simple terms an important property of quantum mechanics. It is called "unitarity" or equivalently "time evolution is described by a unitary linear operator". Obviously, the technical terms would have meant nothing to the general reader, so they were simplified, but they are most definitely not (to quote you) "brain-farts". PS It is more general than a classical state machine. PPS https://en.wikipedia.org/wiki/Unitarity_(physics) https://en.wikipedia.org/wiki/Unitarity_(physics)