Glitches happen.
Oh they certainly do, I went to an ATM this morning to withdraw my pension, typed in the correct amount I wanted to withdraw, collected my cash from the dispenser, counted it and found I had been given 100 dollars more than requested and my receipt showed that I had withdrawn precisely $500 not $600.
I went into bank and told the Teller that their machine had given me more than I requested and was abruptly INFORMED, "Our machines NEVER make mistakes," so I showed my receipt and then counted out the cash in front of her and still got the same response plus a somewhat harsh "Go away and stop being a nuisance."