A breach of unsecured PHI that must be assessed, documented, and reported according to the HIPAA Breach Notification Rule.
Correct. This event constitutes a breach of unsecured protected health information under HIPAA. The Breach Notification Rule requires that the covered entity assess the breach, document it, and follow notification procedures. This includes notifying the affected individual(s) and, depending on the scale of the breach, potentially notifying the Department of Health and Human Services and media outlets. The fact that the disclosure was accidental does not exempt it from breach notification requirements.