Why does the Audit Log for an incident shows as "Response Sent", our customer received a blank email, but we did not send a response?

Environment:

All versions, Incidents, Audit Log

Resolution:

This behavior is due to an agent checking the Send on Save box and then accidentally saving the incident which sends the blank response that the customer sees. The Audit Log shows a response was sent, but it was sent as a blank response and not part of a message.