If the tracks are open, the consist can be deadheaded to Seattle Coach Yard for servicing & turning. According to local newscasts the whole line was closed for awhile due to trees & debris on the tracks. Also consider that if the W/B Builder is running late, there is often not enough time for proper servicing in Seattle. Turning it in Spokane allows the E/B Builder to leave closer to on - time, though servicing quality in Spokane would suffer due to lack of proper facilities & personnel.