The speech Martin Luther is holding was never spoken by him as Luther didn't make a speech after putting on the 95 theses in Wittenberg. The speech is a combination of several writings of Luther from the "Weimar edition, volume 54" which was released from 1883. Furthermore it contains additional lines that suppose to create more nationalistic feeling.
In the movie Peter Henlein died in 1517 during the time of emperor Maximilian I being married only to Ev. However in real life he died in 1542 during the administration of Charles V. and after having three wives.
In the story "The Nuremberg Egg"-pocket watch is created by Peter Henlein. But it is still not know who made it as the first watches of that kind were created in 1550, long after his death in 1542 and other egg-formed watches are from the second half of the 16th century. Also the torsion pendulum, which is the base of these watches were already in use in the early 15th century, long before he was born.
The story of the watch of Martin Behaim which is built by Henlein is pure fiction. Fruthermore Henlein started working on watches in 1512, 5 years after Behaim's death in Lisbon.
Peter Henlein's first wife was named "Kunigunde", not "Ev", as in the movie.
When Peter Henlein's dead body is seen at his funeral he can briefly be seen breathing.
In 1517 Martin Behaim was already dead for 10 years while in the movie is alive.
In the beginning of the movie Martin Behain has returned to Nuremberg from his Kongo-Trip which would set the story in the 1490s. However Peter Henlein is shown as an old man with an apprentice and an own workshop. Henlein started his career as a locksmith in 1509 and started working on watches in 1512. And here he would have been 33 years old.
When mentioning famous people from Nuremberg Ev Henlein mentions the writer Hans Sachs. The scene is set in 1517 when he wasn't as famous as later since 1517 his first big work "Das Hofgesin der Venus" (The hofgesin of the Venus) was released.