Keybase user received notification email for phantom message I did not send

Hi Keybase team,
I had a keybase user contact me today asking about a message that I never sent them based on a Keybase notification email telling them that I had. I tried reporting this within my Keybase desktop client, but am not sure how that would be tracked so I am also filing it here. I'd prefer to not provide the details in a public github issue, so if there is a way to mark this private or come up with an OOB method of communicating please advise.

The report identifies only the Keybase desktop client and a notification email; it names no files, tests, or code entry points. Start by arranging an out-of-band communication method, then investigate whether a message notification was generated without a sent message. Done requires a confirmed cause and a safe resolution path.

Written by the indexing model from the issue text.