nformation in PC can't be reliable, though I can see why she would label it as hacked Pokemon.
Because there's no way to determine if Wish Bagon is legit or not.
Sabresite's legality checker can only check well known event up to Feb/March 2010.
Legality checker can only check Pokemon if it has data of that Pokemon.
For example, legality check will tell you Pokemon you obtained from Pokemon Ranch for Wii as hacked even though it's legit because legality checker doesn't contains data of Pokemon Ranch.
That's why it's impossible to determine event using legality checker(also known as hack checker) and there's virtually no data base for Wish Event Pokemon exist on the internet so it's impossible to check the ID, SID, and OT of it.
So I suppose that's why TwilightBlade put it as hacked Pokemon because there's no way she can determine if it's hacked or not, quite convenient if you ask me.