Continuity mistake: Towards the end of the episode Carmella is reading a book on real estate. When a close up of the book is shown, she is at the beginning of chapter 1, yet when the camera angle changes she is about halfway through the book.
Visible crew/equipment: When Jackie and his crew get to the poker game, an actor's red tape mark (double toe box type) is visible on the floor near the poker table. This will be where Carlo Renzi stands with his shotgun.
Answer: That's not Jimmy, just a look-a-like. Jimmy's short and stout, the guy in "Christopher" episode is tall and medium built. The hair is also different.