Hmmm, my guess would be that he's winging it on his parts but trying to make it interesting. Maybe some of these are from remarks he's heard from the sheeples. Nothing like a good beating from the platform to keep them in line.
Really, most of the WT articles and talks are recycled from within the previous 4 months to 2 years. It's mind-numbingly boring crap. Personally, I would try to include some bit of humor to keep my parts lively. Maybe this dude is trying to make his parts more lively by making them speculative or dropping hints that someone in the congregation should be "marked" or something.