What I was incredulous about was the part of the puzzle's
answer saying the tire with low air pressure would be rotating
"a heck of a lot faster".

The guys on Car Talk have a style of exaggeration that should
be regarded as for listening enjoyment, not quantitative accuracy.

What quantity is "a heck of a lot faster" anyway?

I'm guessing that being 10 PSI low (out of say 30 or 35 PSI) is
only a few percent of difference in rotation speed. It's certainly not
33% difference in rotation speed! But it'll be visibly low, bulging
out to anyone who cares to look, you don't need ABS or pressure
sensors to see that much.

To an ABS system with wheel revolution counters that's easily
detectable (if not "a heck of a lot"!)

And anyway the indirect system won't tell you if all your wheels
are equally deflated...

Tim.