NEITHER TRUE NOR FALSE "Serious computer and digital hardware
  bugs caused by metastability have a fascinating social history.
  Many engineers have refused to believe that a bistable device
  can enter into a state that is neither true nor false and has a
  positive probability that it will remain indefinite for any
  given period of time, "
  [1]https://en.wikipedia.org/wiki/Metastability_in_electronics
  I'm repeating this because I've been looking for this.

References

  Visible links
  1. https://en.wikipedia.org/wiki/Metastability_in_electronics