I think he's pointing out that in a wave state a particle has some uncertainty in its momentum and thus might go from a "higher to lower energy state" so that when it get's measured it's perceived to have a lower energy state than an energy it could have possibly had, however a particle wouldn't necessarily occupy an exact energy while traveling as a wave, it's energy would be undefined which means what you measure the energy at isn't necessarily decreasing or increasing from wave-measurement, it's merely collapsing to a finite energy.