Bodyguard B Ignores Divine Shield

Could it be Guardian messing with it? I mean, can Guardian block magic attacks? Maybe its "block" removes a count if that's the case. The numbers you posted that guarded was about 40% of the total time hit. Just a theory.

I'd be shocked if Guardian was messing with it since I had a Zedbug equipped when doing the testing, which means I couldn't have a shield equipped in addition to a 2h weapon.
Also I realized, during my testing today, that even if I have DS up and Guardian procs, it still counts as a "hit" toward DS's count. I had DS up, got hit 2 times, guardian'd the next 3, got hit again, and DS wore off.

In these two pictures, I have the 2h rolling pin equipped and you'll see I get a "Guard" from the magic attacks of a Ghost Pirate and Spirit Viking.

 Spoiler