I'd like to hear how you reached the "irrelevant" conclusion, unless it's by not reading or understanding posts fully.... however they are irrelevant in this case. The Bank provided a security system which the OP negated by leaving their cards unattended and allowing their PIN number to be discovered by a third party. ...
OP stated that she left the card(s) in a locked hotel room and nowhere is there a statement that she compromised security by writing the PIN anywhere; to the contrary she states she did NOT write down the PIN and that the card was only used to pay the hotel, so shoulder surfing or a fraudulent card-reader in the hotel are the possible causes of a 3rd party gaining access to the PIN. This is because as I already stated chip n pin is inherently unsafe and non-secure. Access to the hotel room was gained by theft, i.e. pick-pocketing the hotel room key from her husband's jacket so in the grand scheme of things, the bank and yourself must believe the OP was complicit in this crime too. I'd also question the effectiveness of hotel security as they allowed multiple crimes to be committed on their property against one of the guests.
The situation you describe is not analogous with OP's. An analogy would be if you used your electronic key-fob to lock your car and thieves intercepted and decoded the signal on a mobile-phone and stole your car using this intercepted data, then I guess you'd be screaming down the phone at the dealer (not at the manufacturer as you have no contract with the manufacturer) to get your car back or a replacement.... If I leave my car keys unattended and my car is stolen. I don't go back to the car manufacturer demanding the value of my car back. I go to the police as it is a criminal matter and not the fault of the car manufacturer as I was negligent. ...
So there you have it, bank customer blameless, bank and hotel both culpable in my view and the case against the bank in particular is water-tight, despite all the wriggling they might try.