This just happened here in Vegas
Put in a 6 teamer parlay. The girl messed up so I immediately went back to have her correct it. She corrected it. Or so I thought. So I walk away and get ready to tell her she messed up again. But the line is super long so I decide to be polite and let everyone else get their bets in before the 9 am games. Line dies down and I walk back to correct it, one of the lines moved so the bet can't be changed 😭😭😭😭