If Siavash had not opened up the competition by his non-voting, we could expect a very boring final few weeks. As it is, he has broken the predictability of Lisa's power base and the competition has been thrown wide open to fair play. By doing what he done, Siavash has taken the risk of (a) being ejected from the show for non-nomination or (b) being a possible evictee if they all go up. In my book, that is taking risks with winning the money, being heavily nominated nearer the final, and being greatly disliked by his fellow HMs. Obviously, Siavash thought the risks were worth taking, and he has the courage of his convictions with regard to a level playing field.