During the fight between Anatoly and Leo, Anatoly's shirt rides up just as he stabs himself. The knife does not go through the shirt. But in a later scene where he is taken away a bloody hole in his shirt is seen.
Leo and Raisa are standing in Moscow in front of a railway station, it says in Russian: "Moscow Central Station". There is no central railway station in Moscow, but several stations where the trains leave to different directions.
Most of the uniformed officers and non-commissioned officers have no orders, medals, or ribbons on their uniforms. Since they all appear to have been in their jobs for years, they should have been wearing at least a few of these, especially since most are at the right age to be World War II veterans.
Mother of the killed boy says he was Leo's godson. This implies a religious affiliation, which in Stalinist times would have been an impossible thing to a high ranking officer of the Soviet army/militia.
When Leo convinced Raisa to travel with him to Moscow to continue investigation into Alexey's son death, she is leaving her work-place without any permission. This is a crime worth of one-year imprisonment, but nothing happens to her when she come back.
All the officers seen are wearing shoulder board insignia. The insignia shown, with the blue trim and blue center strip are indicative of the "Aviation Branch". Based on the duties and locations of the officers, they are definitely not Aviation. The shoulder boards should have red trim with a red stripe signifying ground forces.
While General Nesterov wears Colonel's shoulder boards, all officers are wearing the gold parade boards. On the service uniform, the boards were olive with their branch colors indicated by the service stripes(single for company grade officers & two for field grades). The stars are correct in size for the ranks. As a General Officer, Nesterov should have had the double, wide red stripes on his pants.
Raisa's friend is taken away by police and drops her coat in the gutter. Different camera angle shows the coat on the sidewalk. Then it is picked up twice. After the 2nd time another camera angle shows that the coat wasn't picked up but a scarf, then thrown back down into the gutter.