Weird Outlook Behavior...Drag/Drop from calendar to mail icon adds unknown required attendees.

I have a screening recording of a weird outlook behavior. Anyone that can figure this one out gets two gold stars.

When the user creates a new calendar entry without any attendees, clicks on that calendar item, and drags/drops it onto the mail icon, it automatically adds two required attendees: Chris Norman and Brian May.

If the user adds anyone as a required attendee then it doesn't add Chris Norman or Brian May, it adds just the required attendee.

I've opened a case with Microsoft, it's been open for two months and they don't have a clue.

Any help is greatly appreciated.