The concept of single party consent to recording a conversation implies that at least one participant of a conversation consents to being recorded. James O'Keefe was that one party in all of his recordings, since he was an active particpant in the conversation. None of the participants in the conversation in Mitch McConnell's office gave their consent. The people doing the recording were not part of the conversation.
Does that clear that up?
Guessed you missed my hidden sarcasm tag.