Honestly and I don't think it will happen but here are my thoughts anyway.
Oscar goes an apologize to the man personally in person.
Someone is going to get reprimanded maybe the crew that handled the flight.
It's too soon to fire Oscar since he just started about a year and a half ago and an airline this size doesn't change overnight.
UA should go over to VX, AS and JetBlue and see how they run their operations and see if they can bring some of their fine customer service and culture to United.
Retrain crew and ground staff on customer service especially gate agents: give them the leeway to go above and beyond for inconvenienced passengers like rebooking on a competitor flight or something. i.e. if there was an earlier flight to Louisville on a competitor airline on the same day.
I don't have status on UA but sometimes they go above and beyond to get me there same day on economy when I missed my flight or weather delays.