The definition of mistake is quite broad. Not all parties may agree to what is and isn’t, requiring litigation, but the transfer itself isn’t a done deal until a very lengthy process has been exhausted.

Of course it can. Zelle and your bank may not be keen on doing it, but it’s no less reversible than any other transfer.

And for fraudulent transfers, Zelle’s trying to pin them on the customer is them hoping you’d give up rather than remind them that regulation E governs it as well, and they used to acknowledge that on their web site.