The claim was about ATM withdrawals and credit card swipes. Ie, without a GPS clock there would be a "clock sync" error in the ATM machine, and no cash could be drawn.

I continue to remain EXTREMELY skeptical of this claim. It makes almost no sense.

Please note that GPS is not the source of time, NIST is, and you can get NIST time in a variety of ways including over the internet if needed. And as I have been describing, many of these described errors are around systems with one source of truth (ie, not google spanner type globally distributed databases). So they make even less sense.

Note I'm familiar with clock skew issues and errors in authentication and other systems. These issues show up when errors are in minutes and seconds not microseconds.