Other mistake: In season 5 episode 7, Tony is talking about JFK, and said he was in grammar school when it happened. However, in this episode Tony celebrates his 47th birthday. He was probably born in 1960, so he would have been no more than 3 years old and not in grammar school when JFK was president. (00:26:36 - 00:38:02)
Other mistake: The set up of Dr Melfi's office makes no sense. Her office is in a building with other doctors,yet there's windows on the right side of her office where another doctor's office is.
Other mistake: In the scene where Paulie Gualtieri goes to confront "Feech" La Manna at the bakery concerning the landscaping feud, the clock on the wall doesn't match the time on La Manna's watch or the clock on the wall behind La Manna's desk. The big clock says 11:55 while the other two say either 2:45 or 9:10.
From Where to Eternity - S2-E9
Other mistake: When Tony comes into the bedroom to see Carmella after he and Pussy kill Matthew, the bedroom door seems to be on the wrong side of the room. (00:49:48)
The Legend of Tennessee Moltisanti - S1-E8
Other mistake: Christopher Moltisanti fires a 2nd warning shot at a baker. The shot is fired at the floor but a mirror up on the wall behind the baker shatters. In the next shot and all subsequent shots, the mirror is undamaged. Now this gun was a prop gun, supposedly modified to fire blanks. How did the mirror shatter? It couldn't have been part of the planned shot. Christopher was aiming at the floor. (00:18:41)
Johnny Cakes - S6-E8
Other mistake: AJ and friends enter the club in the city at night but the check for the liquor has 2:34 PM printed on it. (00:20:10)
Irregular Around the Margins - S5-E5
Other mistake: The Soprano crew takes Christopher out to a cornfield to talk some sense into him or whack him. It's raining and the ground is wet but only Tony B is getting wet. (00:41:18)
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.