PHILADELPHIA (AP) — A jury was unable to reach a verdict in the trial of a Delaware man who admitted he broke a thumb off a $4.5 million statue at a Philadelphia museum.

Michael Rohana was attending a Christmas-themed ugly sweater party at the Franklin Institute in December 2017 when he entered a closed exhibit of ancient Chinese terra cotta warrior statues. Authorities said Rohana, 25, took photos while posing next to a statue known as "The Cavalryman," then removed the valuable relic's left thumb and made off with it. The incident was captured by surveillance cameras.

The vandalism outraged Chinese officials.

Though Rohana didn't deny he snapped off the digit and took it home, a jury deadlocked Tuesday on charges of theft and concealment of an object of cultural heritage, The Philadelphia Inquirer reported. Rohana's lawyers argued he wasn't charged under the right law.

"These charges were made for art thieves — think like 'Ocean's Eleven' or 'Mission: Impossible,'" federal public defender Catherine C. Henry said in closing arguments. Rohana "wasn't in ninja clothing sneaking around the museum. He was a drunk kid in a bright green ugly Christmas sweater."

Rohana, a shoe salesman who lives with his parents, told jurors it was a dumb mistake.

"I don't know why I broke it," he testified. "It didn't just happen, but there was never a thought of, 'I should break this.'" He added: "Every time I see this video now, I'm trying to figure out, 'What was going through your mind? What were you thinking?' I don't know how I could have been so stupid."

A mistrial was declared. Federal prosecutors said they'll decide by May whether to retry the case.

The thumb was returned to China. Franklin Institute officials told the jury it has not been reattached.