Ultimately, that's what happens when it's a human that gets the final sign off. You can put all the control and checks in place you need, either the human validates the case and events like this happens, or the computer has final authority and people complain about lacking human touch and comprehension and "they know me for decades but I can't get 20 euros out without several proof of identity".

I'm not sure which way I would consider best. I guess as long as banks are stepping up to their errors and fixing them immediately as in your case, I prefer that.