One thing many career criminals have is time. In jail many of them spend a great deal of time trying to figure out how to game the system and others. For some it is sending the same letter to numerous lovers or potential girlfriends telling them they are the only one for them and they are sorry for their actions, then asking for the lady to put money on their books. For others their time is spent flooding the jail or prison with inmate requests for services, programs or resources, and then figuring out how to parley denials into civil suits.
I forget what the numbers were, but when i worked in Sac. County a couple decades ago there were hundreds of these nuisance suits filed every year by inmates at the county jail and Folsom prison. Most were dismissed, but some actually had to be fought by state attorneys on BOTH sides.
Provided this guy's grounds for the suit are weak, you should prevail.