Season 2, "Honor Among Thieves", in the last five minutes, and possibly earlier in the episode - I didn't notice the slip-up until then. When Mr. Chernus returns home and the camera circles his head, he clearly has two ears despite having one removed earlier in the episode.
They never verify that the ear received was his, the daughter takes off with it immediately after receiving it, as well as taking the finger originally received. However, they do remove part of his ear, which is clearly seen in all shots of his right side.