Note to PBS: Mute your moderators' microphones.

When Sen. Bernie Sanders, I-Vt., launched into an aside about the Vietnam War during the Democratic debate Thursday, a moderator could be heard muttering "Oh, God," into her microphone.

PBS NewsHour anchors Gwen Ifill and Judy Woodruff asked the candidates about race relations, income inequality and Wall Street reform. But there were also a lot of unintended contributions from background noises that included people coughing, drinking water and whispering, as none of the microphones used that evening were ever muted by the debate production team.

As a result, Ifill and Woodruff could be heard whispering to each during the debate, and the most noticeable moment occurred when Sanders addressed Clinton's earlier boast that Henry Kissinger thought she did a fine job when she headed the State Department.



"[A]s Sanders opened with some Vietnam talk, one of the debate's moderators—apparently unaware her mic was still on—could be heard sighing in the background, 'Oh, god,'" Gawker reported. "It was the reflexive response of an antsy kid who just had to listen to grandpa talk about his Iraq war vote for the 52nd time, and if you weren't paying close attention, you almost certainly, would have missed it."