Why would they send the episode out if there’s a chance there was an audio error?
I seriously doubt that's what happened here, but there
are occasionally major post-production screw-ups on these shows that somehow don't get caught. There was a TPIR earlier this season where the sound dropped out almost-but-not-quite-completely for about five seconds because they evidently started making an edit to the audio but never actually finished it.
If you want something more noticeable, there's also an episode where Rich never introduces Bob because they edited out his original introduction and forgot to insert the new one.