A player forgot to pick up level 60 shoulders from a boss in Uldaman. Fortunately, the Postmaster was generous enough to send them a Level 70 version of the item!
The affected item is Pauldrons of Immutable Truth. Wilduk1 forgot to loot the item level 278 version from Uldaman, but fortunately, the Postmaster sent them a level 70 version instead.
Source: Reddit