Went out there specifically without Treasure Hunter trait on myself, but with a friend with it to do some testing cause... why not.

Spinel Quadav - 0/101 (Treasure Hunter 0)
Topaz Quadav - 1/40 (Treasure Hunter 0)
Topaz Quadav - 1/7 (Treasure Hunter 8-9)

She (the thief) just got lucky I says!