They kept the witch. They had to. A good plot never defeats the villain until the last reel. Thus Gretchen Jones made the final four on Project Runway, even though her outfit was ghastly. April Johnston, a weak sister from the very first, was finally eliminated for AGAIN designing a sexy Halloween costume.
The other three finalists are Michael C, Mondo, and Andy. Michael C, in effect, won the challenge. Yes, the same Michael C about whom Gretchen earlier in the show had commented, "I don't know if he's an idiot savant or just an idiot."
Maybe he's just a nice guy loaded with talent.