An economist dismissed testimony from the star witness testifying against the AT&T-Time Warner merger as “very complicated” — and got a nod from the judge.

Testimony by the University of Chicago’s Dennis Carlton drew agreement from US District Court Judge Richard Leon. “It’s like a Rube Goldberg contraption,” Leon said of the complex economic model on which the Department of Justice is basing much of its case.

Leon had expressed skepticism on Wednesday after the DOJ’s chief expert, UC Berkeley professor Carl Shapiro, tried explaining the model’s particulars.

“I look forward to rereading your testimony,” he told Shapiro. “I’m not sure I got it.”

The DOJ’s argument hinges on AT&T’s ownership of DirecTV, which theoretically stands to gain from carriage disputes an AT&T-owned Time Warner might have with other pay-TV distributors.

Those distributors would be willing to pay higher fees for content from Time Warner’s Turner networks out of fear of losing customers to AT&T’s DirecTV in the face of blackouts, Shapiro testified.

He said the same dynamic could also embolden AT&T to charge more for Turner content, knowing its DirecTV unit might pick up customers defecting from distributors who don’t pay up.