Actually this damage on the eagles neck has nothing to do with the obverse die failure. Even in it's terminal state the reverse of the B-5 does not show this kind of "wear" and in lower graded examples of a TDS the reverse details are all present.
Good question. I don't have the coin in hand at the moment. I ran across the photos of it and posted them. Next time I open my safe deposit box I'll grab this coin and check it out.