Ru'Bha Stonewall possible bug

[Dekoda]

Platform: Windows
ISP: Comcast
Type of Internet Connection: Cable
Internet Connection Speed: 30 Mbit/s
Date & Time: 7/14/2014 Approx. 4:30 PM CDT
Frequency: All 5 times I fought him probably, the first 2 or 3 times I popped him I stayed back and wasn't able to notice anything, didn't catch on until the last two.
Character Name: Bruno
Race: Tarutaru
World: Siren
Main Job: Beastmaster
Support Job: White Mage
Area and Coordinates: Grauberg [S] - (J-11)
Party or Solo: Solo
NPC Name: Ru'Bha Stonewall
Monster Name: Ru'Bha Stonewall
Steps: I talk to the Watchful Pixie for the quest Succor to the Sidhe, initiate the fight, and then Ru'Bha Stonewall and the 4 Sentinel Wivres spawn. Everything is normal up until when he uses Invincible, and does his usual back to back Skull Smashes. When he does Skull Smash though, he's hitting himself each time with them for 0 damage. I did this fight five times, on the first two times I was staying back and wasn't paying attention while my pet handled everything. On the third one when I was more comfortable to fight with my pet, I noticed the animation for Skull Smash looked a little weird but didn't think too much of it. Then on my fourth pop I paid a little more attention to my pet's HP and noticed it wasn't moving at all during his Skull Smashes. So before my fifth and final spawn I turned off all of my filters and during Invincible I saw:

"Ru'Bha Stonewall uses Skull Smash.
Ru'Bha Stonewall takes 0 points of damage."

I thought during this it may be an issue with pets exclusively (I was using BraveHeroGlenn at the time I actually saw the Skull Smashes hitting himself for 0, but I believe I used BloodclawShasra on the earlier fights if that matters at all.), but was able to get hate from my pet during his repeating Skull Smashes and he was still hitting himself even when targeting me.

[Dekoda]

didn't realize there was a template edited my original post

[Karbuncle]

Yah, If i recall each time he uses Skull Smash on himself his DEF/MDEF increases, which is why he spams it when Invincible (though hes suppose to use it on you occasionally lol)... Its been a long time since i've done that fight though... but I think I remember documenting this back when it was a SMN Kite > Magic BP fight.

Its like when the Peists in Pashhow casts poison on itself to give itself regen... a unique behavior.