Realised this today. I've a ranger with +3 DEX bonus. He fights with two short swords and looking at the rolls I realised that he is getting his DEX bonus to damage on the offhand attack without having the necessary two-weapon fighting style class passive (he's only level 1) Works to my advantage at the moment, but should be fixed
Still broken, even in patch3/4.1.89.3171. I really hoped to see these kinds of engine/gameplay/rules bugs fixed, these have been known for a long time. The game seems as broken as in patch2, almost nothing was fixed in this regard.