It doesn't trip the Legality Check, but you're right, that is suspicious that the caught date hasn't changed. It may have been imported using Pokecheck, since I don't know if that changes the caught date or not. But it looks legit. Trade it or don't. Your call.
okay and thank u. all the info match up, the only thing that dose sound fishy about this poke is its date, cause its on date on it is the exact same date as when it was released and i have heard that when a poke is tranferred from one game to another the date is suppose to change