A great deal of 'poetic licence' was put into the 'advising' for this film in my opinion. I understand that the advisor may have been an English chap who in his own right is a gun collector and firearm historian. The film are based on a number of facts and they are as I state in this contribution.
Many aspects of this film are based on fact. By using key names and facts all of what I now state should be readily available for anyone to read for themselves on internet.
In the film we see the minister of religion murdered in front of his congregation. The true facts are as follows - During the Maori Wars the Rev Carl Volkner was taken by his ex congregation, the Hauhau rebels and hanged in front of his church. He was then taken down and his head cut off from his body with an axe . His blood was collected in a chalice and together with his head taken into the church and used in a ceremony that parodied communion. The blood was sipped from the goblet by members of the congregation and then Kereopa a prophet plucked the eyes from the head and swallowed them whole!
The Spencer shown in the film - In truth no Englishman had a Spencer that I know of - The true facts are that the rebel Maori Te Kooti had obtained a Spencer carbine and when the English soldiers and Colonial forces were armed with Callisher and Terry carbines the rebel maori not only outgunned them but had the very latest of firearms, the famed Spencer. He carried it with him and used it to affect until a surprise attack saw him make a quick escape with the Spencer loaded with only one cartridge which he fired at the pursuing forces. The Colonial forces thus captured his last 20 rounds and left him with an empty gun.
At the end of the film the Maori rebel is captured and killed but in truth the Maori rebel Te Kooti lived long past the wars and was given a 'pardon'
Ironically enough the Spencer in the hands of the Maori warriors was not the only case of a Maori having the most revolutionary weapon of its time. Years earlier a South Island maori had a Flintlock revolving rifle. This rifle can be seen today in the Otago Museum. It is a Collier and even today is in superb condition.
The Maori were cunning fighters and often taken too lightly by the British and colonial forces. They built forts very similar to the forts in the American West. At first these forts had rifle pits to fire at the British from shelter and as soon as the British brought cannon into action the Maori simply made their living quarters and trenches underground. In one case the British bombed the Maori fort (called 'Pa') for hours and hours then rushed in to find it empty - only to find that the very ground below them erupted in gunfire and in that moment the British lost 31 or so killed outright, 10 or so to die later and in total over 107 casualties. This battle was known as the Battle of Gate Pa. In other battles the British fared even worse with in one battle Poverty Bay, Nov 10 1868 there were 70 killed and at Mohaka, Hawkes Bay on !0th April 1869 there were 60 killed.
At the end of the day the Maori were simply overcome by force of numbers.
To me the most interesting fact is the story of Te Kooti and the Spencer carbine. He also had I believe no less than four revolvers. The most common revolvers used in the Maori wars being Adams, Tranters and Colt Navies.