There is no Federal tort law from what I gather and the law of the state, Texas in this matter, becomes binding in a tort action. We were subject of a malicious prosecution suit. You may see no wiggle room, I know what I went through so something does not compute, either we are talking of something different or your research is not complete.
It’s lengthy, 47 pages (I’ve read it en toto) but here is everything that you ever wanted to know about qualified immunity. http://www.njd.uscourts.gov/atty/3dCirqual06.pdf