Jan Kubis did not commit suicide in the basement. He died in the fight inside the main section of the church.
The movie's climax - with echoes of The Wild Bunch (1969) - notwithstanding, the Germans only had 5 slightly injured soldiers while laying the church to siege...not the dozens who are mowed down and/or blown up with ease by the Czechs - as the resistance only had pistols and limited ammunition against the grenades and sub-machine guns of the Germans. (unusually the portrayal of most Germans entering the Church with machine guns instead of rifles isn't an anachronism, they deliberately collected enough for en mass use due to the confines of the church)
Heydrich was attacked on the 27th of May and died of his injuries on 2 June 1942.
The weapon that wounded Heydrich was a modified British No. 73 anti-tank grenade - a cylinder 11 inches long and 3 1/2 inches in diameter - not the anti-personnel fragmentation grenade used in this film. It exploded near the right rear tire and was not thrown into the vehicle as depicted in this picture.
Heydrich wears incorrect rank insignia throughout the entire film. Heydrich's rank, that of Obergruppenfuhrer (General), was denoted by a three leaf collar patch with two pips. Heydrich instead wears a three leaf patch with one pip which was the insignia for Gruppenfuhrer, or a Lieutenant General.
The reticle in the telescopic sight,when aiming at the train is upside down.
During the fight in the church one of the Czechs gets shot and falls from an upper floor. When he hits the ground, it is clear that it is a dummy that falls.
Just before Jozef Gabcík meets up with Jan Kubis after the parachute jump, it stops snowing for three seconds.
Near the end of the film, where Gabjeck pushes the smoke pipe back out the air vent, and starts shooting at the truck, two Nazi soldiers fall down as if they were shot. Not even in 1942 could a bullet change direction after being fired.
Both Heydrich and Hitler wear pre-war Nazi Party and SS uniforms throughout most of the film - Heydrich in a black SS uniform with swastika armband and Hitler in a brown Nazi Party jacket. By 1942, when Heydrich was killed, all SS personnel wore field grey uniforms and Hitler had by this time adopted a grey soldier's coat which had replaced his older style brown jacket.
As some German soldiers run in the street to attack the commandos hiding in the church, a modern bus is visible as it passes behind the German armored vehicles in the background.
At the assassination site, more modern streetlights line the streets than would have been present in 1942.
In the scene with the SS Officer's wedding Heydrich refers to him as "Leutnant" which was the German Army of second lieutenant. He should be addressed as "Untersturmfuhrer" (2nd Lt) or "Obersturmfuhrer" (Ist Lt).
The same officer is addressed correctly by Karl Frank whilst discussing the fate of Lidice later in the film.