There are times when you can see a train wreck happening in slow motion, but the spectacle of it is far too amusing to stop.
It feels different than regular schadenfreude, watching someone walk into a horrible mistake that is too funny to intercept. It's not a matter of being mad at someone or wishing for their downfall, it's more like pulling up a chair to a live rendition of "America's Funniest Home Videos."
Most of us have been on either side of this coin at least once - the person with pie on their face, or the audience member passively cheering on their humiliation.
Back story: My fiance and I were sitting with our laptops on our coffee table last night, when our beagle/hound mix crawled under my fiance's legs. He stood up to retrieve his phone from another room, and Tito jumped backwards to get out of the way.