Bateman was pulled over for a cracked windshield. The officer suspected that Bateman was drunk, and got him out of the car for FSTs. Bateman was generally uncooperative and may have resisted arrest (the decision only alludes to some of the most important facts here and doesn't really put them in context. Strange that the court would do that, since the stop was recorded, but whatever. At some point Bateman pulled his hand away from the officer and said "No" while the officer was trying to put him in some kind of wrist lock. But at a later point, Bateman put his hands on the car and said "I'm not resisting.")
Eventually, Bateman was thrown to the ground and suffered a traumatic brain injury. He sued the officer and the department. The trial court dismissed the suit based on qualified immunity, and Bateman appealed.
The tenth circuit held that there was a legitimate factual dispute over whether or not the force used was excessive, but that whether or not the level of force used would have been excessive hadn't been clearly established in 2005 (when the stop took place). The court made a point of mentioning that this case was decided before Novitsky v. City of Aurora (which related to the amount of force that can reasonably be used against intoxicated people. It's one of those that I'll eventually be adding to this website). I don't think Novitsky is all that on point, but apparently the tenth circuit wanted to draw parallels.
Anyway, the Tenth held that the officer was entitled to qualified immunity because this happened before Novitsky, but that the lawsuit against the city can proceed.