audioengr
Digital is sampled, not continuous. The reproduction accuracy with digital is a function of the sample-rate and filtering to "smooth" those steps.
The Fourier Transform proves otherwise, and the transform really has more than one proof. One is in the video, but there's mathematical proof, too, if you really want to dive deep into it.
The Nyquist theorem is true and often cited, however, it makes some assumptions such as the waveform is continuous and not transient.It relies on the Fourier math.
Transient waveforms cause the Nyquist theorem to break-down ... the sample rate required to get an accurate transient reproduced is much higher that Nyquist would predict.
If you could disprove the Nyquist Theorem, you'd be famous. It's already been proven. That's why it's a theorem.