Appointments opened in Archive Explorer Placing Duplicates on Calendar

Has anyone seen this before?

Have a user in a data hold, meaning his Exchange mailbox is archived daily - everything is archived. When he opens an appointment in Archive Explorer, it will place 5-6 copies of the same appointment on his calendar in outlook. First thought that perhaps these were appointments with several updates and was EV archiving each one? But, that is not the case. I witnessed him open one that had no updates and it displayed the same behavior.

I'm stumped. I can't duplicate it, and, as far as I know, no one else is experiencing this.