Irregular Around the Margins - S5-E5
Audio problem: From a front angle, Tony tells Adriana about how good his doctor is. Cut to a side angle and Tony's voice is out of sync with the image. Then back to the previous front angle and the audio syncs perfectly.
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.