Not understanding what you are sharing. What is the relationship between the flattening and the missing metal on the obverse?
If they used a tool on the obverse to "cutout" that segment they likely just put it on a flat surface. The downward force of removing that section pushed the area down, which also flattened the reverse area - the "O" in ONE. A lamination will not affect the opposite face of the coin as it's a separation of layers. also since the toning is the same in the area as around it, one can summise it happened a very long time ago. Also in the bottom right area it looks like some of the metal was folded up.
As to what Clawcoins was saying. The area on the reverse is a direct result of the obverse being damaged. But I believe the coin is not missing metal but it took a hit. The displaced metal is on the reverse where it is flat.