Unfortunately, that box of ammo had been opened by someone. Probably purchased, shot a few from a couple different guns and got the ammo mixed up, refilled the box and returned it hoping nobody would be the wiser. Then the store trusted the customer, and resold it as unopened. I've encountered this same thing a number of times over the years at mom and pop gunstores. Sometimes wrong caliber, or worse a handful of lousy reloads, which really frosts me. This is precisely why many gunstores don't accept ammo returns.
