It wasn't very hard because all those people were running with admin accounts when they inserted the CDs in question.
One would hope that on critical Boeing ATE machines (1) the day-to-day operations are not done with an admin account! and (2) autorun is disabled anyway.
The problem with Windoze users running with their admin accounts 100% of the time was bad enough that Microsoft went totally overboard with UAC in Windows Vista, largely creating a self-defeating "solution."