Ruzhan's low Exposure is Overriding stronger Exposure from Frost Bomb

Casting Frost Bomb on top of a boss so that Ruzhan hits the enemy with his attack causes exposure to be capped at -13

When Frost Bomb is cast away from the boss so that Ruzhan's melee swing doesn't hit the boss, then the bosses enters the Frost Bomb, exposure goes well beyond -13