Don't mislead him. The truth is that their banning system is hella inconsistent.
According to the GameFAQs source given, there's a 100% chance this is hacked. It has a few ribbons that you can't get on it unless it was D/P/Pt origin, and there's evidence it came from Gen 6. Personally, I wouldn't risk it. It is otherwise legal other than a few ribbons it has, which wasn't mentioned here but only on the other source.