Mishandling comes in many forms. A couple of nights ago I was traveling on UA from COS to SLC, with a connection in Denver. Checked my bag in COS just under two hours ahead of the first segment.
When I landed in SLC, I was one of the first people off the plane and immediately went to the baggage claim area. Encountered a stopped carousel with about a dozen bags on it, from the DEN-SLC shuttle flight that landed about 40 minutes before my flight. This flight had been delayed getting out of Denver.
Sitting on the stopped carousel is my suitcase. I doubled checked the bag's bar code tag, and it definitely had the later flight's number (the one I was actually on). For whatever reason, the Denver mishandled the bag and put it on the wrong (earlier) flight.
I can't really complain as I probably saved 15 minutes minimum of waiting time, yet the incident made me uneasy. Uneasy from the standpoint of their mishandling, and the potential security issues of a traveler and his bag going on different flights.