The Butler Did It (A Bird in the Hand) - S1-E3
Audio problem: In the first scene, we see a quartet led by a sax player. The music we hear, however, is of a trio without sax. This is fixed in the rebroadcast where the song is Satin Doll led by the sax. Additionally, the piano now sounds like an electric to match its look.
Testimony of Evil (Dead Men Don't Laugh) - S1-E6
Continuity mistake: At the start, the glass on the left is poisoned. The guy picks up the glass on the right, but still ends up dying.