Nobody's denying that the bank fucked up, and in this case they are going to pay a heavy price (lawyers aren't cheap, and they'll be lucky to get 50¢ on the dollar for the liquidated assets). This point's not under contention. Banks have a large incentive to get transfers correct for a number of reasons, so bringing up that banks should be penalized for making a mistake is in my opinion irrelevant, as they often are.
The better question to ask is, what kind of society do we want to live in? One that protects property (and aims to correct mistakes related to incorrect transfers of property) or one that says its ok to blow someone else's money on whatever we feel like because someone made a mistake. We're all investors here, and we entrust a large amount of money to companies that we expect to be financially responsible. As index investors, we're removed from a lot of the checks and balances placed on these companies to ensure semi-fiduciary behavior for investors. But we're protected by other investors who ensure money is being spent appropriately and government laws and regulating institutions that also ensure our money is not being blown away. I don't think anybody would argue that a fiduciary responsibility for someone else's money is a bad thing.
Last analogy: Let's say a carpenter is going to work on a house, and he sends a part-time helper to the house a week ahead of time to place cabinets and tools under the porch. Unfortunately this helper misheard the house number and therefore dropped them off at the wrong house. When the homeowners of the incorrect house arrive and notice all of this equipment in their backyard, they also happen to notice the owner's information all over the equipment. A week later, the carpenter arrives at the correct house and doesn't see any of the equipment; the correct homeowners haven't seen it either. The carpenter finally gets a hold of his helper, they realize the issue, and then he goes to the house where the equipment was dropped off, only to not see the equipment under the porch and to be completely ignored by the people inside (meanwhile he sees a fancy new RV out front). What would you do if you were the carpenter in this situation? What should be the laws governing property that is accidentally placed in the possession of someone who is not the lawful owner? What if the placement wasn't even accidental; what if the carpenter was working on a house, left his tools there overnight, only to come to finish up the next day and realize his tools were pawned because the owners of the house felt the tools now belonged to them since they were on their property? What about a bicycle that is placed on public property, is that ok to take since it isn't in someone's personal possession? By that logic, shouldn't it also be ok to cut the lock on that bike, since someone who walked up to it can now claim it is in their personal possession?
I'm really struggling to understand others' perceptions of where property rights should exist, especially in the case of a mistake. My understanding is property should be transferred at agreed upon terms between two parties. When a mistake is made (such as when a cashier accidentally charges me too much (or too little) for an item at a supermarket), both parties should be able to lawfully rectify the situation in accordance with the terms of the transaction.
Sorry for being longwinded, it's probably time for me to bow out of this conversation.