I used to work at The Apple Store. And that's really the way it should work. However, from my time there, we had credit cards declined all of the time. The Apple Store is a huge place for fraudulent purchases and credit cards routinely auto-blocked access when purchases were for Apple and outside of typical purchases. We actually had the VP of BOEING's
Business credit card declined. The standard procedure was to have the customer call the bank, validate that they were them, and that they indeed DID want to make the purchase. After about a minute, we could re-run the card and it'd work.
Now, when the payment device asked for an Override code, it was the job of the EMPLOYEE to got to the back and call up the bank. We're provided special numbers to call and special codes we have to type in. It's a horribly clunky and long process which everyone hated to do, but that was it. So, this is completely the employee's fault - albeit it's really a training issue and the blame rests with Apple. I can totally see why an employee would
#1) Not want to go through that process when they need to get to the next sale
#2) Possibly be new and not completely understand the process
#3) Be susceptible to some clever social engineering - ie: There are some cases where the customer must call the bank. I need an override code from the bank to process this. The customer is calling the bank, so that means I don't have to!
So it's a big f-up, but I can totally understand how and why it happened.