He might have uploaded it to pokecheck, or he might not have. Either way, it is likely the same Mew appears multiple times on pokecheck so you have no evidence to prove he offered it for trade or not. The only person that can check is Pokecheck himself.
However, the pkm files aren't necessarily created on pokecheck, and even if it was, that hardly means it's hacked, it just means there's a pkm file of it up on pokecheck. What I do know is that that Mew is very likely not hacked. Even if he did download the pokemon off of pokecheck, if it is Bond's, it's fully redis and would be redistributed all over the forum anyway.
As it is, even if you do get him blacklisted, it's not going to solve matters. People are still going to download whatever free stuff they want off pokecheck and trade them all around the place. If it bothers you that much, maybe you shouldn't be trading so much. It's not as big a deal as you seem to think it is.
However, the pkm files aren't necessarily created on pokecheck, and even if it was, that hardly means it's hacked, it just means there's a pkm file of it up on pokecheck. What I do know is that that Mew is very likely not hacked. Even if he did download the pokemon off of pokecheck, if it is Bond's, it's fully redis and would be redistributed all over the forum anyway.
As it is, even if you do get him blacklisted, it's not going to solve matters. People are still going to download whatever free stuff they want off pokecheck and trade them all around the place. If it bothers you that much, maybe you shouldn't be trading so much. It's not as big a deal as you seem to think it is.