PS There are various impact simulators around. Here's one where you can plug in the type, size, and speed of your space rock and see what would happen: https://janus.astro.umd.edu/astro/impact/

And another: https://impact.ese.ic.ac.uk/ImpactEarth/ImpactEffects/

For reference, here is the asteroid he talks about: https://solarsystem.nasa.gov/asteroids-comets-and-meteors/asteroids/apophis/in-depth/

Not enough to do what he describes. However, that doesn't mean a shower of them wouldn't, or that "Apophis" is not a specific rock but a description of the result, or that NASA would tell the whole truth about a hazard.