Destructive Rollback after SC

Let's use a Work Glove as an example.

How you lose items:
Character A puts the WG in storage.
Character B (same account) retrieves it from storage.
*insert lolnexon*
Character B gets rollbacked to when he hadn't retrieved it.
Character A doesn't get rollbacked.
Boom! Item vanished to the air.

How you duplicate items:
Character A trades the WG to character B, a friend.
Character B uses the WG for a while, and gives it back to character A.
*insert lolnexon*
Character B gets rollbacked to when he was wearing the WG.
Character A doesn't get rollbacked.
Profit!! Two WGs.

Items vanished/duped because the rollback was partial, not total.

Oh I see. :o
Rollbacks can be a convinience or a screwover. But it's mostly screwovers =__=