We hired and motion-captured a child for a lot of the motion just after the New Year. We used to layout in the engine, modifying as necessary to make it work in the cut. It was laid out to storyboards that I had created late last year.
We baked out the scenes as they were (messy, choppy and nasty as all Hell) and gave them to the animators who threw away whatever they wanted or cleaned up what they wanted depending on the situation. For example, when the kid runs across the rocks that is mocap that has been stylized to improve arcs and spacing as well as push the bounding quality of his movement BUT the 3 shots afterwards had the mocap binned and were hand animated.
We did what we could till the final rig was ready and then with about 2 1/2 weeks to go we started on the facial animation. The cut changed a bit during the production of so some shots got longer but most they got shorter till we felt we had a cut that we were happy with.
At that point it was a sprint to the last day which was EOD Thursday before the GDC demo. 7 weeks production in all.