When Mestigoit the Sorcerer meets Laforgue, Laforgue is reading the Breviary (daily prayer of a priest). The page is clearly at DOMINICA V POST PASCHA, the fifth Sunday of Easter which falls between 3rd May and 6th June. Yet the action is supposed to be taking place in the autumn-winter of 1634.
Fr. Laforgue is seen baptizing with saliva. Saliva is not valid matter for baptism and no 17th century Jesuit, who knew their theology very well, would have baptized with saliva. He could have melted the snow to obtain some water.
The French characters all speak English. This would normally be overlooked as a conventional dramatic device, were it not for the fact that subtitles are used for the Native Americans.
Near the end, Father LaForgue digs a grave fairly easily with only a shovel in what would clearly have been frozen ground in the dead of winter.
Gourd Rattle is made from a tin can rather than a gourd.
The first line of the Montagnais leader can be heard repeated during his private conversation with Chomina.
In one of the flashbacks to France, Father Laforgue's mother says she is praying to St. Joan. However, Joan of Arc was not canonized until 1920.
In one scene, the current flag of Quebec can be seen flying. However, the flag only came into existence in 1947, 313 years after the setting of the movie.
The French girl plays a recorder solo from 'Der Fluyten Lust-hof" published in 1644, while the film is set in 1634.
In the early ceremony / party scenes, and occasionally later, some of the natives' feature headdresses incorporate tail feathers collected from male ringneck pheasants (Phaisanus colchicus). This species was not introduced to North America until 1773.
Chomina, left behind to die, says to the priest: an Algonquin word translated as "go," then "Black Robe," and the first word again. The subtitles, added here as to any Algonquin dialogue, substitute "my friend" for "Black Robe." This considerable shift in meaning, added in translation, is not compatible with the character.