If there was only one guy on the plane, none of this would have happened. I've been on flights which were overbooked. Before boarding, someone comes on the intercom and asks if anyone would like to trade their ticket for a later flight, some number of air miles, and a small cash gift. I have yet to see the police become involved.
This time nobody took the offer. (I have heard conflicting reports of $800 and $1000 being offered, probably in travel credits rather than cash.) Then one of the people who lost the lottery had a meltdown rather than leave the plane.