Historically, the "tanks" used by the Germans during the suppression of the uprising were actually French light assault guns Lorraine 37L - which means there was not a single Tiger tank (not to mention two). Also, the SS troops were "police" and training/reserve units (rear formations), not the front-line troops.
Many of the German rifles are Spanish 1916 7x57 Mausers, and not the typical Axis or captured rifles (e.g., VZ 24, WZ 29, etc.) used by German police or rear-echelon troops.
In the final scenes, Tosia Altman appears largely unblemished. The caption says she was "captured a week after her escape from the ghetto and died in the custody of the Gestapo", implying they probably killed her. In reality, Tosia was injured in the face and leg before going down into the sewers. She then hid with other Jewish fighters in a celluloid factory. On 24 May, an accidental fire broke out in which she got severely burned and was forced into the open where police captured her and turned her over to the Gestapo. She died of her injuries two days later.
When the "German" soldiers are marching into the ghetto they count to four in Russian.
The "Polish army uniforms" in the opening of the movie are actually Soviet Rifle Division uniforms from the 1944-46 period.
In several shots, notably the overhead shot of the Tiger tank, it's clear that the German troops are not marching at the pace of the sound effect.