1813 Trade & Nav, Split Planchet Or Split Die ?

Struck on a defective/cracked planchet. As evidence, there appears to be strike weakness above the crack on the reverse rim. It would also be unlikely that two die cracks of the same size, directly opposite of each other would appear.

A full strike by two dies can fuse the metal on each side of the crack to varying degrees. I think for this example, the wear has obscured the planchet crack on the edge. I would bet that when this piece was fresh off the press, you could see the full split along the edge.

edit: It is also important to note that this planchet crack could have appeared during strike, but I'm not sure how to distinguish between those created before and during strike.