Halo: Reach Trailer False Advertising?

Is it just me or does the Halo: Reach Trailer have nothing to do with the game? The trailer where Kat is running with some sort of bomb it seems and she gets killed by a banshee and noble six comes and takes the bomb and leaves her and takes it up to the ship and throws it onboard. However in the game there is no bomb at all and Kat gets killed by a sniper not a banshee. The covenant ship is destroyed by the Mac cannon noble six fires and thus ends the game. The trailer is a bit misleading wouldnt you say?