I can only speak for what we do, which would not resolve the uVerse or the DirecTV examples (they're not our customers), but I would gather their process isn't much different.
For a particular show, we have a master default record. Since Bob Barker has been the host for the most episodes, their record most likely has him as the listed host for a default episode, or they simply haven't changed it over to Drew Carey. That would explain the situation with The $100,000 Pyramid with John Davidson -- since at the time it was switched to the most recent host, but never switched back.
The default record is used in cases when particular episode information is not given. In the case of a season pass, CBS has likely not given all of the episode information yet or it is still waiting to be processed, so the default will be used. About the only thing I have contributed to our system since I've been there is we now also have default season default records as well, so in the case of TPIR we would use most recent season's default.
The Bill Cullen one is likely operator error, whether human or algorithmic. Again, I can't speak to how much human vs. automation they use, but we do not use automation at the network level. Each network has a small staff dedicated only to a particular network's listings, so they innately understand the patterns both the networks and their affiliates would generally use.
Also, it could also be a misapplication of the data at the head-end level. I know that we given some customers a complete cast list of a default show, so they could be cherry picking off a similar list. As long as the show is correct, 99% of the complaints and quality control issues are taken care of. There's just not enough cost/benefit for the customer to be that concerned about accurate cast listings.