Those guys are shady! Even one of the bartenders overcharged me and when I called him on it, he didn't even give me a refund and followed up with a phone call to the manager next day, all he said was sorry.
More BS, not BBC!

We are human, and mistakes do happen. Also many of us lose our keys and our glasses more often than we would like.

Bartenders live off their tips and overcharging customers will almost always costs them their tip. A bartender is more likely to undercharge and hope to enlarge their tip than overcharge and lose a tip.

Customer service issues are always difficult and the answers are more art than science.

Courtesy and indifference are very lacking in the service industry today. In the end if the staff tries hard and is courteous that goes a long way in my book.