The torch is held in the opposite hand from the blade/blunt, but same hand as the bow. The shield is processed differently, as it is only held when the weapon hand has a weapon in it, although there is some similarity between the shield replacing the torch, and the bow replacing a blade/blunt. Bottom line is probably that blade/blunt
can be used at the same time as a torch, but a bow can't ever be held at the same time as a torch.
None of that explains why the crashes happen, but it does explain why the circumstance is unique.