Yes radial pull does exist. There are minor variations, not defects, in the tires that can cause this. It is usually noticeable on vehicles that are sensitive to leads and pulls. Sometimes swapping tires side to side can fix a small pull that the alignment specs don’t show. If the pull is fixed, hooray, don’t worry any further. It most likely won’t re-occur when you rotate the tires.
And by the way, weights on the tires do no affect the alignment. They are there to remove the vibrations from minor variations in the tire and wheels.