You just ruined your own argument. "She's left a component off her dish FOUR times for the judges." and "Top Chef is not cumulative - at this point she's getting by just because she's cooked good food previously."
If Top Chef is not cumulative, then they are only judging Dawn on the dish she puts out in each, single episode. And in their minds, her dish(es) was/were not the worst dish of the challenge even without the missing ingredient. For all we know, they may have said "okay, everyone, you cannot count the [missing component] in tonight's judging."
The only requirement is th