Patrick Gillen is a lawyer for the Thomas More Law Center and was counsel to the Dover school board during Kitzmiller v. Dover. His opening statements are here. And yes, he is not just a cynical lawyer taking whatever case he can get, but a real Intelligent Design Creationism proponent who has defended creationism in several other situations as well. He is liable to use whatever argument he can take, from Taliban-style Bible scholarship to appeals to POMO, different ways of knowing and incommensurable conceptual schemes.
His other main area of expertise seems to be sueing public institutions in Michigan for offering domestic partner benefits to same-sex couples (also here). Would you be surprised to learn that Gillen is not always ideally honest? Gillen was indeed one of the people behind Michigan’s Proposition 2, banning same-sex marriage, and co-author of a referendum explicitly saying that “Proposal 2 is Only about marriage” and should not affect other benefits.
Diagnosis: A breathtakingly dishonest crank and morally bankrupt human being. And as with so many of those, he ends up in the Taliban-land of fundie denialism. Dangerous.