Visible crew/equipment: While Sal and AJ are at the batting cage, Matt starts telling AJ about the German philosopher Nietzsche. As the camera moves backwards in this dolly shot, we can see two metal T-marks on the ground, as well as the dolly track at the left side of the screen.
Visible crew/equipment: After Tony enters the garage and finds AJ smoking pot with his friends, when Carmela walks in and comments about the smell, the reflection of the boom pole/mic moves across the car's windshield.
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.