Answer:
The Staff Interpretations to Reg E state very cleary that consumer negligence cannot be taken into account when figuring consumer liability. As a result we must look at the liability schedule as provided in section 205.6 of Reg E. Since the bank was notified within one day of the loss, the bank must limit the consumers' liability to $50.00 per individual.
Also VISA provides Zero Liability protection to any signature based purchases.
I would recommend against issuing the negligent couple another set of cards and repeating this exercise again.
First published on BankersOnline.com 7/4/11