A large percentage of files in a CG production are not shot specific, so no, the recovery work was definitely not wasted. There are sets, lighting setups, props, layouts, models, textures, shaders, character rigs, procedural and effects systems, etc., etc. A few of those things might have to be redone, but when those things are set up and the script changes, the main bulk of the work is cameras and character animation, and then re-rendering.