There's a lot to unpack in this story, so let's get to it.
Allison Preiss was traveling to her friend's bachelorette party via a United flight. Unfortunately, one of the chairs on the airplane was broken, so United needed a passenger to voluntarily offer up their seat and take the next available flight. But no one volunteered... So the airline looked through the tickets to see which passenger had purchased a ticket at the lowest cost. It happened to be Allison. They removed her from boarding, and refused to refund her any of the cash she paid for the ticket. Many airlines also offer a cash voucher in exchange for a passenger to give up their seat. The airline refused, and would only offer a $10,000 voucher.
But don't get too excited at number! Often vouchers like these have extreme blackout dates, and you can only use it towards one trip. Meaning, she better fly first class to Australia or something. If she just uses just a couple hundred of it, the remainder may end up back in United's pocket.