The following combination can lead to poor quality on a crafted item, even with the Blacksmith trait (crafted items are at least normal) 

Smith:
Dragonkin - Combat Slave

100 Phys; 14 + 20 wit

Good quality Mythril Hammer(Ironwood handle) 

Item built: Adv. Heavy armor. 

E:; A 2nd Smith w/o  trait was potentially involved

yeah, currently it only works so the one character who finishes the item is calculated