Avery's lawsuit against the county was very weak. He was not going to win that. He may have been able to settle it for right around what the state paid him anyway.
The documentary trumped up everything in the defense's favor. If you do a little research, you'll find that they found that key the FIRST time they actually did a full search of the house. The first 3 times they searched the place, they were only looking for specific things and were only in the house for a very short period of time. The key also has his sweat DNA on it.
Add to that, they found his blood in her car and his sweat, and proved that the blood did not come from the vial.
He stalked her. He specifically requested her. He drew plans of a torture chamber while in prison. He had been accused by multiple women of rape, other than the false accusation. He purchased the exact shackles his nephew described. And more...