There's a small error at 5:32. A neutron star's mass is not 10-25 solar masses because it does not retain ALL the mass of the parent star, but rather most of what has been the parent star's core.
And there's a significantly lower limit to how massive a neutron star can get. Given their absurd densities, above 2-2.5 solar masses, neutron degeneracy pressure and other nuclear forces at play can no longer prevent complete collapse (to a black hole).