Horses are shod with modern nailed horseshoes. The most probable horseshoes at the time of Alexander should have been leather and plants "booties" of Asian origin. In the 1st century, Romans used leather and iron "hipposandals". Nailed iron horseshoes seem to have become adopted much later.
Knick knacks in Olympia's boudoir include the Sumerian Goat and Tree excavated at Ur, in modern day Iraq, by Leonard Woolley in 1927. Created and buried more than 2000 years before Alexander was born, it's unlikely his Mum had one on her sideboard.
[Director's Final Cut] At Philip's wedding, when Attalus is toasting a Macedonian Queen to be proud of, he pauses to glare at Alexander but as he does so, his dialog continues without moving his mouth.
In the final battle, before Alexander would ride towards the elephant, he is seen holding a spear, even waving it and pointing with it to his men to move forward. One second later he is carrying a sword, with the spear nowhere to be seen.
In the Final Cut, when Alexander is giving his speech to his men at Gaugemela. The officer who hands him his helmet is on his right, but in the next scene he is on his left handing Alexander his helmet.
When Aristotle is describing what he thinks might be a route to circle around to the headwaters of the Nile and travel down it to conquer Egypt, he refers to going "up the Nile," rather than down it. This may be due to the modern map convention of showing North at the top of maps and referring to traveling in a northerly direction as going "up". The Nile River flows from South to North and thus traveling down the river is going North.
In the "Director's Cut," Ptolemy implies that Alexander and Hephaistion died of typhus, which is transmitted by lice. He refers to what Hephaistion drank, so the cause is more likely to be typhoid. Historians believe that typhoid killed Alexander because waters of Babylon were, and still are, notorious for it.
Although Cassander is a main character, and leads the cavalry under Alexander, his actual role in history is much smaller. He is first recorded in the year that Alexander died, sent by his father to Babylon. This gave rise to the idea that he came with poison that eventually killed Alexander.
Alexander asks Darius' daughter how she wishes to be treated, she replies, "like a princess," and he grants her wish. In reality, Alexander asked the question to the Indian king Porus. When Porus replied "like a king", he won Alexander's respect and became one of his allies.
When the men mutiny at the river Beas, Craterus speaks of 'these elephant monsters' implying that the Macedonians have only heard of them. This is ridiculous, because not only had they already fought the battle of Hydaspes (depicted in the film as after the mutiny), but they also would have seen the elephants at Gaugamela (Darius had brought a few elephants to the battle, but they saw little action).
On road marches (as opposed to marching to contact, i.e., when the enemy is in sight or there is imminent contact), the 4 to 7 metre (13 to 21 feet) sarissa would have been broken down into its two components for ease of transport. In the movie, the sarissa is always shown at full length deployment.
On the map of the known world, the Black Sea is correctly called "Pontos Euxeinos," but the Mediterranean is called "Mare Mediterraneum." On Roman maps, it was called "Mare Nostrum" (Our Sea) or "Mare Internum" (Inner Sea). In the fifth century BC, Herodotos called it the "Pontos Boreios" (Northern Sea).
In the film, the final battle against the Indians is depicted as taking place in a jungle, whereas in reality the battle - known as the Battle of the Hydaspes - took place on the banks of the river Hydaspses (now known as the Jhelum).
After Alexander tells his army that they'll leave India and march home to Babylon, Ptolemy narrates that Alexander marched his army "directly west across the great Gedrosian desert, seeking the shortest route home to Babylon". This is somewhat inaccurate. While Alexander did march his army through the Gedrosian desert, it certainly wasn't the shortest route home to Babylon. In fact, going through the Gedrosian desert was by far the most dangerous route possible and certainly not the shortest route. The only reason Alexander decided to march through the desert was for his own glory, because no other army had ever crossed the desert alive, and he wanted to be the first to hold the honour of doing so.
As Alexander comforts a dying Hephaistion, he tells him that they'll set sail from Babylon and conquer various peoples and lands, one of them being "the Roman tribe" as Alexander describes them. Being a well-educated man, Alexander should have known that the Romans were not just a mere "tribe", but were a fully functioning republic by 323 BC (when this scene took place).
The film depicts Alexander deciding against pursuing Darius after the battle of Gaugamela, instead turning back and coming to Parmenion's aid in battle, resulting in years passing before Alexander continued searching for Darius. In reality Alexander actually did pursue Darius immediately after he fled the battlefield, and for several days Alexander chased him relentlessly across the desert - almost without any water - before reaching him mere moments too late, since he had already been betrayed and killed by several of his commanders.
Many scenes were re-ordered in the "Final Cut." For example, Alexander's childhood is seen in flashback, not at the beginning, in chronological order. However, the end credits are the same, so the list of actors "in order of appearance" is inaccurate.
The goof items below may give away important plot points.
Nearchus and Antigonus are shown to pursue Pausanias, murderer of Philip and then spear him to death. This is inaccurate. In fact, Nearchus, along with Ptolemy, would not have been present at Philip's murder.