After the men set the crematoria 4 on fire they tore down the fences and fled into the woods. They barricaded themselves in a barn where SS caught them. They were burned alive inside the barn.
The film features the historical Sonderkommando revolt of 7th October 1944. After multiple plans for an uprising had failed in the past for different reasons, the Sonderkommando finally mounted the uprising in a hurry, not as carefully planned as shown in the film. The crematoria IV Sonderkommando members suddenly rebelled after they knew they were about to be liquidated. They had no guns and used only blunt weapons and self made grenades and only set the crematoria IV on fire. Expert Andreas Kilian criticized the representation of the revolt in this film as "exaggerated" in a 2014 article. The cinematic depiction in O Filho de Saul (2015) is the most accurate yet.
A few exterior shots show four crematoria chimneys close together. In reality crematoria 4 and 5 were located quite a distance away from the other two.
The movie suggests that two crematoria were destroyed during the rebellion. In reality only Krematorium 4 was damaged.
According to all available witness reports and historical accounts, there never was an incident like the one presented in the scene, where a Sonderkommando prisoner beats a Jewish victim to get his watch. This is not based on historical facts, but a dramatic invention. Historian and Sonderkommando expert Dr. Gideon Greif criticized in a lecture from 2016 especially this scene among the many mistakes he found in the film. Greif argues, that there is no logic to it, because the Sonderkommando members simply had to wait until after the execution to find as many watches and valuables as they wanted, because they had to take care of the clothes and leftovers anyway. It would have been irrational and even dangerous to use force on the victims before the execution, because it might have resulted in serious punishment or even death through the observing SS soldiers.
When the Jews are ushered from the changing rooms to the "desinfection shower room" a woman with a bikini top is visible for a moment in the background.
After the execution some of the extras are visibly moving their heads and hands.
When a large column of victims is being escorted to the gas chamber, under serenade by the camp orchestra, a closeup of the orchestra drum player shows a modern day snare drum with metal tuning screws, a plastic drum-head, and an aluminium drum stand. None of these existed in 1944.
The real Josef Mengele was a tall man with a full head of thick black hair. The actor who portrays Mengele in the film looks nothing like the historical doctor and is short and bald.