Technically you did, but it doesn't matter... :asd:
I hope someone creates a trainer that unlocks all the achievements soon...
If Microsoft ever catches the irregularities in how long it took between unlocking the Achievements, they might start tagging cheaters on the PC like they're doing now to the Xbox 360 side, and we don't want any of this to happen.
I don't want my gamertag tagged as "cheater" because I also have an Xbox 360. So just unlock the Achievements progressively.