I just read this whole thread thinking "Doesn't anyone watch Top Chef?" The Mystery of the Black Gunk, like The Mystery of the Disappearing Purée, will be studied hundreds of years from now by television scholars like professors do with Jane Austen now, think the producers.
Someone asked what about the model getting to take home the spoilt dress, wouldn't they just make her another of the same material (or patch the current dress if possible) without the time pressure? It might come out better. In fact, they might do that for all of them, fixing any obvious flaws caused by the rush.