Various bosses (notably Black Mage and Slime) have inconsistent and strange drop formulas. Items that used to be instanced are sometimes shared. In Black Mage everything is shared and in every boss Black Eternal Rebirth flames are shared. It used to be Honor, Flames, and armor/weapon drops were instanced. There was no mention of this being changed in the Destiny patch notes, and the patch notes even confirm that this is not intended.
The following boss rewards will be changed from individual rewards to shared rewards:
Occult Cube
Rebirth Flame Lv. 110
Rebirth Flame Lv. 120
Rebirth Flame Lv. 130
Rebirth Flame Lv. 140
Rebirth Flame Lv. 150
Production Soul Enchanter
The following boss rewards will be changed from shared rewards to individual rewards:
Medal of Honor
Boss Medal of Honor
Zakum's Soul Shard
Hilla's Soul Shard
Papulatus Soul Shard