Apademak Issue - Leveling up after it is stunned

[Kitheren]

My linkshell and I were fighting Apademak the other night. We had one devoted stunner, if I recall correctly. A black mage. Unsure if he was subbed red mage or white mage.

Our first few fights went off without a hitch. He never leveled up and it died quick enough.

Our last two, on the other hand, were not so easy.

Our stunner did in fact stun Apademak. We received the "Apademak's casting is interrupted." message. The problem comes in where although he was stunned he leveled up anyway and began to pwn us with Fulmination. It was very strange. Each member of my alliance read the interrupted message and knew he was stunned however he leveled up.

The other Apademak went fine except for the resist stun which enabled him to eat us. But except for the strange level up while stunned, every other fight was normal.

Platform:
Xbox, however most of my alliance was on PC.

ISP:
Verizon Fios

Type of Internet Connection:
Fiber Optic

Internet Connection Speed:
I couldn't tell you @_@

Date & Time:
April 16th, around 2am. Possibly later.

Frequency:
Once

Character Name:
Kitheren

Race:
Mithra

World:
Leviathan

Main Job:
White Mage (90)

Support Job:
Red Mage (45)

Area and Coordinates:
Abyssea - Uleguerand, around F-6

Party or Solo:
Alliance, about 8 people

NPC Name:
None

Monster Name:
Apademak

EDIT
I was just watching my husband fight Apademak with my linkshell. It was able to use Fulmination without leveling up. Is there a chance it is perhaps broken?