Wow, wut a random glitchy game.....after failing the mission 6 times, finally walked out of the roof door and a checkpoint was saved for me.....
Another thing, when I walked out the door, I planted an incendiary bomb near the entrance, yet G22 guys just ran up behind me on the roof.....did they spawn or come up the ladder? if they spawned, that's pretty lame....there's something rough around the edges with this game but I see why it has a bit of a following.....