I went and boxed your mew on my 3DS, got the same as HMM's, so that settles it (I didn't know this happened, I should check how trash bytes are handled in the different games and generations, best case scenario would be that some stadium game erases them completely...).
We have 3 different saves and all 3 mews are the same, alongside the fact that they used savestates (and with it, they were distributing cloned Mews), but still I'm sure someone would appreaciate a 100% confirmation of different distro consoles providing the very same Mew.
Now, when is that pokebank update coming?
ps: RupeeClock, I was refering not to the dump method itself, but if he had done another trade before dumping the savegame, as I was thinking that maybe trading again was what changed the trash bytes.