A jury has acquitted a Chicago man of helping plan the 2008 attacks in Mumbai, India that claimed at least 164 lives. But his attorneys are vowing to fight the two counts on which he was found guilty, including helping a terrorist organization. The split verdict caused some confusion about how the jury reached its decision.

Tahawwur Rana’s jury will remain anonymous. That’s pretty rare. After the verdict, jurors weren’t seen. They left court through a back way out of the media’s eye. They convicted Rana of helping a Pakistan-based terrorist group and of helping plan an attack against a Danish newspaper that never happened. But they acquitted him of the most serious charge: helping his friend plot the Mumbai attacks which rocked India’s largest city.

Rana’s defense attorney, Patrick Blegen, didn’t have an answer for how the jury reached its conclusions.

“It’s always difficult when you have separate charges that are tried together because you’re always worried that something is going to spill over onto another count or that the jury just decided to split the baby in half, as they say,” Blegen told reporters after the verdict.

The not guilty verdict could’ve been because the defense argued Rana wanted to take a trip to Mumbai with his wife right around the time of the 2008 attacks. Or it could’ve been because Rana was warned not to go to Mumbai. Defense attorneys asked why would he need to be warned if he were involved in the plot.

As for the guilty verdicts, maybe the jurors were persuaded by the fake business cards Rana made for his friend, David Headley, so Headley could pretend to put an ad in a Danish newspaper he said he was planning to attack. Or maybe it was the secretly-recorded conversation between Rana and Headley in which the two discussed potential attacks and mentioned Denmark.

A room was set up for jurors to talk to reporters, but none of the jury members showed up. Federal prosecutor Patrick Fitzgerald made it simple: prosecutors failed to prove Rana knew about the Mumbai plot before it happened.

“I’m not disappointed overall,” Fitzgerald said. “I’m disappointed in one charge being an acquittal but very gratified overall because the other two charges were very serious.”

Fitzgerald said investigators prevented one attack from happening: the Danish newspaper attack, but also many more. He said they did that by arresting David Headley, Rana’s friend, and flipping him. Headley testified against Rana and told the FBI about dozens of other potential plots.

“We would be crazy if we would sit around and say, ‘You know what? It’s all about Mr. Headley. And all we want to do is put him in jail and sit around and let attacks happen,’” Fitzgerald said.

Rana’s defense attorneys say Headley got a sweetheart deal from prosecutors. By testifying against Rana,  Headley is avoiding the death penalty and extradition to India. Fitzgerald said Headley’s not going anywhere for quite a while and the investigation into these plots is ongoing. That’s because six other people were indicted with Rana, but they aren’t thought to be in U.S. custody. One of them, Ilyas Kashmiri,  was reportedly killed in a drone attack last week, but the U.S. government has not confirmed that.

As for Rana, he sat expressionless as the judge read the verdicts. His attorney, Charles Swift, said there was more behind that blank face.

“I think he’s in shock,” Swift said.

Swift said an appeal of the two convictions is likely. Rana’s other attorney, Patrick Blegen, hinted at the possible strategy. He told reporters the split decision may suggest the verdicts contradict each other. But Patrick Fitzgerald seemed to downplay that angle.

“Jurors don’t have to be entirely consistent, but I don’t see an inconsistency here,” Fitzgerald said.

Rana will be sentenced in a few months. Of the two guilty counts, each carries a maximum of 15 years in prison. Defense attorneys and prosecutors will likely argue whether the 50-year-old Rana will serve those 15 years at the same time or back-to-back for a total of 30.