You can see the sway is already beginning to heave that Ford around by the :18 sec mark. Either this driver was texting, eating a pizza, and changing waypoints on his GPS… or he didn’t have trailer brakes. I mean seriously, how could you let this go? There appears to be plenty of time to tamp this down. By :26 it looks like its probably not recoverable.
I know I’m preaching to the choir here, but remember: hit the trailer brakes (only!) in a sway event; or accelerate… or both. That’s the best option for straightening it out.