When Assane is talking to Juliette in the park, the neck of his coat is mostly lifted, but in one shot (near the end of the conversation) it is lowered. After that, it's up again.
While Assane listens to the Four Tops record, the line "I'll be there / to always see you through" is heard twice even though it's really only sung once.
It's impossible that J'accuse doesn't hear nor smell not just one but two strangers entering the apartment. Still, it doesn't bark or do anything else.