The opening title card say that John Rae's expedition, where he learned of Eskimos meeting the Franklin expedition survivors, took place in 1850, four years after the expedition got stuck. It actually took place in 1854, eight years later.
Despite the sub-zero temperatures, the water vapor cannot be seen in the air when the men exhale.
As Sir John Franklin and Commander Fitz-James go to return to the Erebus, Sir John descends into the boat first. According to naval protocol, the senior ranking officer is always last to get into a transport vessel, and first to get out.
The officers generally speak of wintering in the arctic as though it were uncommon, undesirable, and unplanned-for. Yet it was extremely common for exploratory and whaling vessels to spend 1-3 winters, given how short the summers were. In fact, though the show presents this expedition early in its first year, the ships become lodged in sea ice at the start of their second winter. Franklin prepared his ships with stores he thought might stretch up to seven years.
At 4:47 Francis Crozier talks of "massive guano deposit off Namibia." The Republic of Namibia was not founded until 1990. Even the Namib Desert, where Namibia derived its name from, was known as Great Southern Zahara at the time.
There is a tense discussion between Sir John Franklin and Sir James Ross regarding the voyage. The action takes place in 1845, before the expedition departs. Actually, by that time, Ross had been appointed the British consul to Denmark, and did not return to Britain until 1850, after the expedition had gone missing.
Captain Franklin give the name "James Ross Strait" to a body of water he says the ships have been successfully traveling for the summer. Later, he states the ships have not yet reached sight of King William Land, and he wants to sail southwest while Crozier prefers to sail east around what he rightly suspects is really King William Island.
Yet James Ross Strait is to the east of King William Island. The ships could not have already been traveling in it while still north of the island, and once they were in it, they would already be committed to an eastern route. Instead, it was Peel Sound and Franklin Strait that took the ships south towards King William Island.
Yet James Ross Strait is to the east of King William Island. The ships could not have already been traveling in it while still north of the island, and once they were in it, they would already be committed to an eastern route. Instead, it was Peel Sound and Franklin Strait that took the ships south towards King William Island.