When Shia LaBeouf posted a 12-minute short film online on Monday, it drew plenty of attention — but also suspicion over its resemblance to a graphic comic.

On Tuesday, the actor apologized. “I’m embarrassed that I failed to credit @danielclowes for his original graphic novella Justin M. Damiano, which served as my inspiration,” LaBeouf wrote on Twitter. LaBeouf’s short, also about a film critic, was called “HowardCantour.com,” and sites like Buzzfeed and Wired on Monday posted about the similarities in theme and dialog.

“Copying isn’t particularly creative work. Being inspired by someone else’s idea to produce something new and different IS creative work,” LaBeouf wrote. “In my excitement and naiveté as an amateur filmmaker, I got lost in the creative process and neglected to follow proper accreditation.”

He went on, “I was truly moved by his piece of work & I knew that it would make a poignant & relevant short. I apologize to all who assumed I wrote it. I deeply regret the manner in which these events have unfolded and want @danielclowes to know that I have a great respect for his work. I f—-ed up.”

The short, starring Jim Gaffigan, debuted at the Cannes Film Festival in 2012 last year. Buzzfeed still has the entire short online, even though it has been password protected on LaBeouf’s site. Buzzfeed pointed out that part of LaBeouf’s apology has similarities to a Yahoo Answers entry on the question, “Why did Picasso say ‘good artists copy but great artists steal’?”

Here is the Yahoo user’s comment from four years ago:

“Merely copying isn’t particularly creative work, though it’s useful as training and practice. Being inspired by someone else’s idea to produce something new and different IS creative work, and it may even revolutionalize the “stolen” concept.”

The opening narration of “HowardCantour.com” opens, word for word, with the same opening in the first panel of “Justin M. Damiano.”

“A critic is a warrior, and each of us on the battlefield have the means to glorify or demolish (whether a film, a career, or an entire philosophy) by influencing perception in ways that, if heartfelt and truthful, can have far-reaching repercussions.”

Fantagraphics, publisher of Clowes’ comic, said in a statement that he “is pursuing his legal options.” Clowes retains the copyrights to his works.