So, I have this game, and this is definitely NOT any US official release of the game (speaking from the cover only).
Also, that isn't even US style packaging. Official PS2 games don't have that "DVD" logo in the corner or on the spine, and the PS logo on the spine is wrong. I agree with Sheep, this is likely a chinese knockoff. Even if he does show you the disc, ask to see the bottom of it, too.
Also, by the time the PS2 was released, ESRB ratings were bold black, not outlined/white