Audio problem: When singing "Goodbye little yellow bird" Emma blows a kiss to Oliver offstage, but she is still singing the song when she is blowing the kiss. Although it's possible she was pretending as it was part of the act, her voice wasn't even muffled by her hand.
Audio problem: When Buck walks to the bar downstairs and meets Mrs. Oates, the sound of their footsteps is that of tiled floor, but they're walking on a rug.
Something Borrowed, Someone Blue - S5-E9
Audio problem: Whenever someone is walking on a rug the sound we hear is of footsteps on a tiled floor.