When the Countess Erdödy's home is hit, during Napoleon's bombing of Vienna, her son is thrown by the blast before it actually hits.
At his first public recital, Ludwig was eight years-old (some sources report seven) and his father announced him as six, yet the movie conveys, via voiceover, that Ludwig was "12 and his father told the court he was nine".
Beethoven's estate was not willed to his Immortal Beloved.
The grave shown at the end of the movie is neither Beethoven's grave as it was in 1827 at Währing cemetery nor is it the 1888 one, when his remains were moved to Zentralfriedhof. It is similar but it is missing the harp golden emblem on the middle of the obelisk, near the top, a serpent emblem of eternity, enclosing a butterfly.
In one scene in the movie, Beethoven preformed the Emperor Concerto but couldn't preform it due to his deafness and in response he received laughter, jeers and catcalls from the small audience which prompted him and his girlfriend to leave. Audiences never laughed or jeered at Beethoven at all during his day. If a moment like this happened audiences would have just fell dead silent in sadness.
The film depicts Beethoven as being deaf for most of his life, even in his youth. Beethoven could still hear slightly until around 1818 when he went almost completely deaf.
Towards the end of the film, the protagonist is seen in discussion with a female who at times communicates with him in a low-tone in order not to be overheard. This would have been impractical however, given that by around the time in which the events surrounding the Immortal Beloved letter took place (the letter is dated 1812), Beethoven had already lost a significant amount of his hearing. Regardless, the composer carries on the conversation as if he wasn't hard of hearing.
In the movie, Beethoven bribes Chancellor Metternich to secure custody of Karl von Beethoven after his brother dies, offering to compose for Austria at the Congress of Vienna. Metternich became Austrian Chancellor in 1821, the Congress of Vienna ended in June 1815 and the legal battle over the custody started only just after Beethoven's brother died in November 1815, months after the Congress had ended. The case was completely resolved by 1820, before Metternich became Chancellor.
The producers of the film made painstaking effort to ensure that authentic late classical-era pianos were used on set, yet the music that is allegedly coming out of them is unmistakably from a 20th-century instrument.
Beethoven plays Für Elise for his nephew Karl, with his arms reaching around Karl's body, whilst Karl sits at the piano. There is no way Beethoven can reach the sustain pedal in this position, yet the piece is being correctly pedaled as we hear it played. Carl is not proficient enough to pedal for himself, let alone for another player, so it is not even an issue as to whether he may have been pedaling - he was not.
Early in the movie, after her bath, she says, "We were invited to Prince Vichnoski's palace, for a musical evening. Beethoven was going to be there." In the following shot, as the horses are approaching the palace, the shadow of the film crew is visible on the horses.