The stretch look makes me think this is a lamination issue. When the metal is cold rolled onto the stock hot roll, the shape is flattened and stretched into a longer shape. Because it was not as hot as the hot rolled metal, it is not fastened tight to planchet. So after the strike it may fall off the coin, or stick around like this example.
CoopHome: Why do lamination errors happen? cold metal rolled on to a hot sheet of metal, will adhere for a time. but a later can fall off the coin or hang onto the coin. depending on the heat of the hot roll temps.