"Prompted by a complaint from the Liberty Legal Institute, a group of Christian lawyers. . ."
These are undoubtedly the individuals who asked Spradlin to be the 'subject' of the lawsuit and will foot all the bills. This is nothing new. The American Atheists (as well as other groups) do this kind of thing all the time - find a 'victim' and file a lawsuit.
I hope Spradling understands that if he loses that he, not the law firm, will be responsible for all legal fees if he loses and the university and the professor asks the judge to assign them. He's really exposing himself to financial disaster.