2 knives, and all survived as he was walking through the hallway..typical nut acting out randomly...no one was left to bleed alone...
where the Calgary incident is done inside house with one knife, and all stabs were fatal, bled and died fast.
out of 5 dead one would have jumped him, isn't that the natural instinct when you see your friend in trouble?....this is why i say Matthew rehearsed his spree well in advance and his plan was solid.... i think he separated them one by one, to places in the house where the other 4 would have no idea what happened to the first, and so on.