This is not a partial collar error or any other kind of error. This is post-strike damage. By 2005, virtually all business strikes were struck with inverted dies (reverse die as hammer die). So if this was a partial collar error, you'd see a horizontal flange without reeds sticking out next to the reverse face. Here we see a normal reeded edge next to the reverse face and a recessed edge without reeds next to the obverse face. A coining press cannot produce a recessed edge regardless of the die setup.