I think the rabbit always has the option to stay in the race. It was one thing when Tom Byers paced Coe and Ovett in the 80's and could occasionally steal a race, but it's quite another when Martin Keino is asked to run 1:50, 2:46 week in and week out for El G.
Really the runners have gotten so specialized at their events that the only runners who could rabbit and also finish respectably are the very runners being rabbitted for.
And yes Zurich sucked this year...though that place still has more atmosphere for track than anywhere else in the world.