Because the judge didn't immediately call FAULT and asked WHERE is a very good, but not 100%, indication of a rat being there. 1) A bedding tube was placed near a rat tube. Or 2) It's also possible there is no bedding tube and the handler was pointing too far away from the rat.
The rule for removing a bedding tube in Crazy8s is if it's removed from the straw before the judge calls FAULT, it's removed from the ring.