I’ve always loved movies — I saw “The Little Mermaid” in the cinema when I was about 2 and a half, and the rest is history. In middle school and high school, I wrote reviews for my parents and other family members to read and occasionally for my high school newspaper. In my 8th grade gifted class, we had to interview a professional working in our area of interest. I contacted Bob Butler, the film critic at the Kansas City Star, and asked him about his work. He replied in great detail and showed good humor toward my teenage-minded questions, and to this day I remember that and appreciate the time he took replying to me.

Much of my journalism experience up to this point relates to opinion writing and commentary. I wrote a column for my high school paper, served as the opinion editor and wrote and assigned staff editorials as editor-in-chief. My first job at the University Daily Kansan involved writing book reviews for Jayplay. I spent my sophomore year as a long-distance columnist before manning the opinion desk for a semester and working on the editorial board for an additional two semesters after that.

The big misconception I see about opinion writing? It’s the idea that, because they’re presenting an “opinion,” a person can say or write whatever they want. Oh, no no no no. The top-quality columns and editorials will involve just as much reporting and research as any straight news story, and it’s these writers’ knowledge of what they’re discussing that makes their voices so critical.

Bearing that in mind, I was surprised to read yesterday on Deadline that Movieline had sacked Elvis Mitchell over an error in his review of the film “Source Code.” According to Nikki Finke’s Deadline article, the studio screened a final cut of “Code” for Mitchell to review. Yet in his review, Mitchell took issue with Jeffrey Wright smoking a pipe in the film — an act that director Duncan Jones said on Twitter had been included in a draft of the script but was cut for the actual film. Yet it ended up in Mitchell’s review. Finke wrote that Movieline formally asked Mitchell to explain himself, and eventually terminated his contract entirely, after he’d worked there a scant three months.

If you’re unfamiliar with Mitchell, just know that he’s no small-timer; before joining Movieline, he worked as a critic for the New York Times, appeared on television and is a fixture on the festivals circuit. For a seasoned critic like him to make that kind of a mistake is almost … scandalous.

The reader comments accompanying the Deadline article are all over the map. Some speculate that he left the film early, or didn’t see it at all, and based his review on a copy of the script he had. Others suggest that he read the script and saw the film, and just got confused. Still others defend him and suggest that we don’t know the whole story. Whether they support him, many commenters suggest that he might be given a pass were it not for other erratic behavior, such as backing out of working on Roger Ebert’s review show and a development program with Columbia Pictures, both missteps that Finke discusses in her article.

Ultimately the only person who knows exactly how or why the discrepancy occurred is Mitchell. Not being in the theater with him, it’s not my place to say that he saw the film or not, because obviously I can’t know. But this episode, which brought down a highly respected film critic, should be a cautionary tale for opinion writers, a lesson telling them to take care and make sure they get their facts right. Film critics — including Roger Ebert — make mistakes all the time when it comes to characters’ names and relationships and even some basic plot points. What probably cost Mitchell was that his error was made not when describing the film, but when judging it. A troublesome mistake, clearly, but one that all aspiring opinion writers should be wary of.