Cipher: Abenzio buyable more than once

Platform: Windows
ISP: Cox Communication
Type of Internet Connection: DSL
Internet Connection Speed: 20Mbps
Date & Time: Dec. 3, 2014 Between 2 and 8 PM PST
Frequency: Once (did not reproduce)
Character Name: Izahk
Race: HumeM
World: Asura
Main Job: Dancer, Lv.78
Support Job: Thief
Area and Coordinates: Windurst Walls, C-13
Party or Solo: Solo
NPC Name: Greeter Moogle
Monster Name: None
Steps:

1) Bought Cipher Abenzio ~11/17/2014 from Greeter Moogle.
2) Trade it to Wetata (Windurst Woods H-10) for Trust: Abenzio.
3) Accidentally bought Cipher: Abenzio again ~12/03/2014 from Greeter Moogle.

Normally, if you have the trust magic already, it says "You cannot obtain the Cipher: xxx. Come back after sorting your inventory."