There's Something About Paulie - S2-E16
Continuity mistake: During scenes with Paulie, in a few shots the two rings Paulie is wearing on his left hand disappear/reappear, and the mole on Paulie's face also vanishes in a couple of shots. Some examples: (1) After Paulie's remark about a coke mule, Lois says, "Peter, living room," then Paulie's mole and rings disappear. (2) While Paulie and Peter are sitting on the swing, Paulie's two rings vanish when the swing collapses. (3) Following the hail of bullets, when Paulie turns and falls onto the puddle, the rings are gone. (00:12:00)