Put it this way... you pay for their technology to be accurate, so their failure is your gain
Years ago I was at an ATM and was withdrawing something like $300 or so. The ATM spit out $220 then froze and said there was an error. I took a picture with my phone and even the amount of money I had. Call BofA and they said they would investigate. I get a letter in the mail a few weeks later saying "here is a receipt from your withdraw for $300"
Id take any chance I have to get their money now