Did you notice Cain grabbing his jacket and heading out? By the time he gets there it will be all over and I thought he would be the one to bring it to an end.
When Marlon had the rifle why didn't he just shoot open the lock on the door? There's no way they could have survived so long in the water and did you see how fast they were able to run after all that!
Or even simply smash a window. When the whole cast were in there, why didn't someone grab a couple of full bottles and brain him? He couldn't watch everyone.
I really liked Cameron earlier on, he loved Debbie's children too, why change him to be so evil. Easy on the eye too (except when he had his evil face on) I must be the only person who will miss him ;)