Oh yes, legit all right... :S You have a 1 in 189,137,100,800 chance of actually getting a Ditto w/ Modest and 4 perfect IVs and that's not counting Synchronize or how rare Ditto are in the wild, much less shiny unless it was found in D/P chaining which is still a 1 in 923,521 chance of finding a pokemon with 4 perfect IVs. You have a better chance finding over 100 shinies. O: