What? If a car is going the opposite direction through the intersection and there's no stop signs on the road you both are on, would you normally stop? I'm reading between the lines here, but this sounds like both vehicles were passing on the non-stop road at a two-way stop intersection. Unless they're signalling, I don't think you're expected to assume they're coming out of their lane to cross yours. By your logic, I should stop every time there's a car coming the opposite direction and there's a driveway on my side of the road just in case the car is going to pull into the driveway without signalling.