I just watched Amazing Grace, which was very good, despite the occasional dramatic license with the facts. But the subtitles were amazingly (haha) full of errors.
For example, Thomas Clarkson tells Wilberforce that he has friend in France, "our counterparts, and they bring me only good news", which is "any good news" in the subtitles. That good news is Revolution: "The Americans pulled the cork out of the bottle, and now the French share the wine," he says, and invites Wilberforce to come to Paris and "drink some of that wine"; the subtitles tell him to "bring"it.
Later in the film Clarkson (mis)quotes Thomas Traherne's "The Salutation" (he omits the word 'lodg'd': "Strange treasures lodg'd in this fair world appear, Strange all and new to me", but the subtitles have it as "in this fair world up here" (which does, I admit, make his admission to his infant son that he has "absolutely no idea what it is about" funnier, at least). Amusingly, Clarkson's "Oh, bollocks" becomes "Oh, bullocks."
And in that vein Richard the butler quotes Francis Bacon's "It is a sad fate for a man to die too well-known to everyone else and still unknown to himself" but in the subtitles it's "fate from a man".
John Newton tells Wilberforce to be "in the world but not of it" and the subtitles have him saying "not off it". And Newton also says that in telling Wilberforce he lived in the company of ghosts he was explaining to a boy "why a grown man cowers in corners" and the subtitles makes that an ungrammatical "a grown man cowards in corners".
James Stephen says in a letter that "Many children are scalded to death by the molten lava" and the subtitles distressingly say "scolded to death".
Wilberforce tells his wife she can't bring him laudanum because he "poured it all away this morning", but the subtitles say he only "put it all away".
Wilberforce complains to Pitt that "You've read my letter but you've not taken in a word of it." The subtitles say "not taken any word of it."
Pitt points out that as Prime Minister he "can't be seen to openly oppose the King" - or, in the subtitles "be seemed to."
Wilberforce tells Barbara that he's "against flowers in church", but bizarrely (for the Evangelical icon Wilberforce) it becomes "flowers and church" in the subtitles.
When William Pitt warns Lord Dundas that if he crosses Pitt and Wilberforce, he, Pitt, will have to "put a pistol to your head", Dundas responds, "If you do, there will be two pistols, one from each side. But perhaps if I duck, you'll shoot each other." And the subtitles say, "if I dock..."
Olaudah Equiano says he survived the Middle Passage because "Your life is like a thread; it breaks or it does not break" and in the subtitles it "wrecks" or not.
And at the very end Clarence defines noblesse oblige for Tarleton as meaning: "My nobility obliges me recognize the virtue of an exceptional common" and the subtitles replace the last word with "talent."
(Also, they missed entirely why Pitt said Michael Shaw and Edward Hope were "both friends" and didn't capitalize Friends, as in Quakers.)
There are a lot more than this, trust me. The DVD is bilingual for Canada and the subtitles were done in Montreal - maybe by a Francophone? Obviously not someone with a script (not that that's unusual for subtitles; quite the opposite.) Fortunately, there aren't rough accents in it - I had them on for the commentary track and kept noticing "I don't remember him saying that!"