It happens. I distinctly recall a few years ago at AA DFW bag claim seeing a bag on the floor at a carousel tagged XXX-DFW-YYY (and YYY was a Caribbean island/resort destination). I went to the baggage desk and pointed it out to the AA staffer sitting behind the desk (after distracting him from the video game he was playing on his phone). His response? "Yeah, OK." And he went back to his video game. That's someone's vacation ruined.