All your favourite movies contain one major mistake.

One of the most essential roles on a Hollywood movie set is also one of the least known. A script supervisor (or a continuity supervisor) works behind the scenes on set to ensure continuity is keep throughout each section of the film. You know — making sure that wisp of hair is exactly so, the wardrobe looks the same in each shot and the props haven't moved around between takes.

It's an incredibly important job and helps bring legitimacy to major productions, especially given how many times a scene can be shot. Everything needs to be precisely the same each and every time.

But of course, we are just humans, and sometimes little mistakes can make it through filming, editing and into the final product for viewers to... notice and later mention online.

And sometimes, some rather large mistakes slip through the cracks.

On The Spill podcast, hosts Laura Brodnik and Charlie Begg unpacked some of the biggest mistakes in Hollywood films that were left in the final cut — some on purpose, some by circumstance and some by... sheer forgetfulness? 

Listen to the episode here. Posts continues below.

10 Things I Hate About You.

10 Things I Hate About You. Image: Walt Disney Studios.One of the most pivotal moments in this classic teen film happens when Kat (played by Julia Stiles) stands up in front of her class to read out a poem she wrote. It quickly becomes clear that the Shakespeare-inspired prose is all about her love for Patrick (Heath Ledger) and in an incredibly heartfelt moment she breaks down crying.

We now know that Stiles never intended to cry, nor was it ever rehearsed — she simply had an emotional moment that ended up being quite perfect. In fact, it summed up the character's relationship peak so well, the director decided to call cut on that one take and use it in the final version of the film.

Watch: Movie mistakes you may have missed. Story continues below.

Titanic.

Titanic. Image: 20th Century Fox.The line, "I want you to paint me like one of your French girls," will forever be etched into our brains. But in the saucy scene between Rose (Kate Winslet) and Jack (Leonardo DiCaprio) in Titanic where he sketches her naked, DiCaprio actually flubbed his lines when he asked her to sit on the couch.

However, what could have been discarded on the editing floor actually made it to the final cut of the film, with director James Cameron keeping it in because it was so funny. And you must admit Jack's bumbling moment did add to the sexual tension in the scene.

The Wizard Of Oz.

The Wizard Of Oz. Image: Goldwyn Pictures.In The Wizard Of Oz, the Wicked Witch finally meets her demise when Dorothy throws water on her. In the film she catches on fire in a dramatic culmination but did you know that actress Margaret Hamilton actually accidentally went up in flames due to her highly flammable costume makeup?

We always thought this was just some pretty impressive pyrotechnics but in reality she suffered second-degree burns from the stunt mistake and had to be rushed to hospital. Given it was only the second take, it was the one they had to use that one for the final cut of the film.

Casino Royale.

Casino Royale. Image: Sony Pictures.When Daniel Craig emerged from the sea wearing a fetching pair of European budgie smugglers in his first foray into the world of James Bond, an icon was born. But the scene in Casino Royale was a bit of a mistake, despite making  the final cut.

Pretty Woman.

Pretty Woman. Image: Walt Disney Pictures.Now this one is less catastrophic and just plain annoying for anyone who's a stickler for continuity. In the 1990 romcom Pretty Woman, Julia Roberts' character Viv can be seen eating a croissant in one shot but when it returns to her in the scene, she's eating a pancake. 

It's hardly worth losing sleep over, but it maybe should've been picked up at a few points along the editing journey. Either way, it made everyone hungry.

Pretty Woman. Image: Walt Disney Pictures.

The Princess Bride.

The Princess Bride. Image: 20th Century Studios.In the 1987 classic The Princess Bride, Carey Elwes' character Westley was genuinely knocked unconscious by actor Christopher Guest when he bopped him on the head with a real sword. Ahh, they really did play it fast and loose in 1980s Hollywood.

Because Elwes had to be rushed to hospital, the director had no choice but to use that take in the final version of the film. If it looks believable, that's because it is.

The Birdcage.

Robin Williams was the ultimate professional, who would continue rain, hail or shine — something he proved in the 1996 film The Birdcage. 

During a scene in which Williams, Hank Azaria and Dan Futterman are in the kitchen trying to figure out what to cook for guests, Williams slipped over as he was preparing to leave the scene — something that would usually call for a director to reset the scene to shoot again. 

But he pushed through and continued acting, resulting in a hilarious on-screen moment with all actors holding back their laughter.

Good Will Hunting.

The enigmatic Robin Williams was back at it with an ad lib scene that just *worked* in Good Will Hunting. 

There's a moment he shares with Matt Damon in his character, Dr Sean Maguire's, office. At one point Williams goes off script, improvising an anecdote about his character's wife farting in her sleep.

The two professionals carried on filming and it resulted in the pair bursting into hysterics. It was just too good not to keep and remains one of the most beloved scenes in this brilliant film.

American Sniper.

Bradley Cooper is used to being on some big budget films, but we guess American Sniper might have been more of a low-key production? In one scene, his character is holding a very clearly fake baby — which is not unusual, this happens all the time given how difficult it actually is to film with real infants.

But it took a bizarre turn when Cooper very visibly used his finger to make it look like the baby's arm was moving up and down. Somehow, that take made it into the final cut of the film. And if you haven't seen it, no, it is not a comedy.

Django Unchained.

Django Unchained. Image: Sony Pictures.

This is not a film for the faint-hearted, with stacks of violence and blood... and not all of the blood was fake, it turns out. 

In one heightened scene in Quentin Tarantino's seventh film, actor Leonardo DiCaprio sliced his hand IRL. As blood poured out, the actor continued on with his monologue, which added to the tension brewing in the scene. 

It was of course included in the final version of the film — a very Tarantino move.

Feature Image: Miramax, Sony Pictures, Walt Disney Studios.

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