I want flawless with dw ability ut jolteon,flareon and umbreon i trade shiny flawless ev training clone terrakion,shiny flawless clone ev training latios and shiny flawless clone ev training garcchomp.
Therefore they would obviously agree with the Celebi, they're from the same event, only the Japanese disc contained Celebi, the rest Jirachi. (as i obtained a shiny jirachi from a disc myself it's obviously possible to get the celebi shiny)
That's what they say about the Jirachi that I obtained myself, saw it shining with my own eyes.
The Celebi seems legit and matches up to the event information 100%. It's passed hack checks, there's always a chance that the .sav was edited, it wouldn't take much to make it appear shiny that way. It would be the only logical explanation.