A 6IV Keldeo is perfectly fine. Gen 4 was the last gen where there were any IV restrictions on what could be caught/obtained via wondercards.
People have hacked in official tournaments for years. At least the Dream Ball was (supposedly) just from a hacked parent or something and didn't affect anything substantial.As a (three time?) World Champion, he sets the standard and needs to be a good example for everyone else. If he gets away with doing even a harmless hack like a ball, then other players who look up to him will think it's okay for them to hack as well.
I recall at some point in either the late 2000s or early 2010s an infamous PokeSav'd Metagross that was floating around that was used by several people in the VGCs or something.
Official hack checks are terrible, they always have been. Whether its the laughable hack-protection featured for PokeTransporter or other parts, they've never been thorough period and just barely even look for things a human does (illegal balls, etc).
They never account for actual bits of data (which is why illegal HA Pokemon were transferable, though to my knowledge they fixed this). Heck, the most "thorough" their hack checks ever got for data investigating... is that PokeTransporter blocks out anything with 255 EVs in a stat. 252 is fine. 253-255 is not. Not sure why...
(his FB post made me laugh, though. How many times did he have to convince himself by having every fifth word be "legit", "legitly", "legitimately", or other variants...?)