Maybe they lost something in retelling here? Made up new stimuli for which it doesn't work because of harmonics or something?
Nope, the audio examples are all straightforward realizations of the corresponding music notation. (They are easy for me to tell apart.)
Still, the notes drag on, the notes have harmonics, etc. It is not pure sine waves that abruptly stop and give time for the ear to 'clear' of afterimage-like sound.
I hear the difference in the cadence, it's just that I totally can't believe it can possibly be clearer than just the one chord then another chord. I can tell apart just the two chords at much lower volume level and/or paying much less attention.
Here's the new thread for posting quotes, with the usual rules: