Ending doesn't make sense *spoiler*

The way Rick Carver explains it in the film is that if one homeowner "won" and kept his home, then many other homeowners would follow suit. So they would lose their deal with Vesco because Vesco probably wouldn't want to be dragged through the court system.

Carver was indeed that cool and calculated type. Even if cops/FBI in suits arrest him I bet he could get a deal by implicating others as is the norm in movies. Little fish help DAs catch bigger fish and are let off the hook.

Nash was little fish, Carver was bigger but he was working with crooked people like county commissioner Link and the grey bearded man, Freeman, working for Vesic Investment Group. Elected official, commissioner Link and grey-beard forge documents for Carver. He has leverage. I bet Carver would have worked the system and gotten off the hook in movie universe justice system.

Another thing that bugged me was the Greene family eviction. Frank Greene is so broke he can't pay for electricity and water. He's apparently been unemployed for two years. Surely he's behind on his mortgage payments. Clearly he's going to get evicted and bank will take the house. Now we find out there's a technicality that supposedly stops or postpones the eviction? How can that be? In movie/TV justice systems we a taught to hate technicalities. Usually technicalities let murderers free because of typos in warrants or such things.
What is a proof of publication? It had something to do with his mortgage being sold from the lending bank to another, then again and again to be packaged as an MBS. Why does it matter?
Finally in the armed stand-off Frank Greene says something about cancelled cheques. So he was paying off his mortgage? That would be easy to prove. With what money was he paying it?
The film would have been a lot better with a more cynical ending.

Ya kindof a huge plot hole

Films like these really aren't supposed to be dissected, although I often do. They are primarily meant to stir discussion and bring attention to certain societal issues or to bring about change. I thougt this film was good but suffered from unrealistic Nash family story in terms of the homeless unemployed entitled granny turning down a nice home because....her hard working son worked for someone she didn't agree with. Right. Never in the history of man has someone walked away from a bought home because of that. Prove me wrong and I will post a Youtube video of myself eating THREE HATS.

as Aupple says underneath, Carver's concern was that if Greene won his appeal, others might follow. I never understood how Carver came to this conclusion, because the situation with the missing document was a one-off, and, as others have said below, would only have delayed the eviction anyway, so I can't see that others would follow.
Furthermore, it's made clear throughout the movie that there are countless other foreclosed homes in the area, so if Greene had been successful, and, say, another 10 or even another 25 people decided to appeal theirs with the same legal team and somehow won, they could easily have replaced them with other homes for Vesco's portfolio.
I personally think it was to do with Carver always wanting to win, rather than being about the money. Even if Greene's home was of little significance to him, and could easily be replaced, he just didn't want to lose in court. It ties in with what he said to Nash earlier about how "America bails out the winners, it doesn't bail out the losers". He wanted to stay a winner.

And, to end on a petty note, Vesco wanted 100 homes, so he was actually risking the profit on 99 homes for 1 home - hence the title of the movie. Actually if you want to take it further, he was risking his licence, his reputation, his freedom, everything, for 1 home. But like I say, he'd gotten so used to winning and was obsessed with always making the maximum profit and not missing an opportunity to capitalise, it's what had gotten him where he was when he made the deal with Vesco. He wasn't going to suddenly change his personality and accept defeat and write off 1 home. He lived and died by his opportunism.