Who was the one that couldn't keep track of all the dead people and what did he say in the death of Stalin

[Ralph Yozzo]

This is what New York City has in store. 

In the movie, that distinction belongs to Vyacheslav Molotov (played by Michael Palin), the Foreign Secretary who is completely blinded by his fanatical, terrified loyalty to the party line.

Because people are being executed, imprisoned, and rehabilitated at a dizzying pace, Molotov loses track of who is currently considered alive, dead, or a traitor.

The most famous manifestation of this happens in a conversation with Nikita Khrushchev. Molotov is passionately defending Stalin's erratic purges, arguing that anyone arrested must have been guilty. Khrushchev reminds him that his own wife, Polina, was arrested.

Molotov tries to save face by strictly following the last official narrative he was given, saying:

"I am a true card-carrying member of the collective leadership! If Stalin says she's a traitor, then she's a traitor, and I hate her!"

Shortly after, Lavrentiy Beria (the head of the secret police) reveals that he actually had Polina secretly released and kept alive as a political bargaining chip. When she walks into the room, Molotov is instantly thrown into complete cognitive dissonance.

Having just screamed that he hates his traitor wife, he instantly bursts into tears, hugs her, and seamlessly switches gears without missing a beat, sobbing:

"Polina! My love! I knew you were innocent!"

It perfectly encapsulates the film's dark satire: these powerful men are so terrified of slipping up that they will rewrite their own reality, memories, and personal relationships on a second-by-second basis just to survive.