I checked this model. There are many twisted non-planar quads in the obj. I'll think how to improve my importObj script for using it with such complex models.
The scripts works well with other complex models with non-planar quads .
for example:
http://www.craftsmanspace.com/free-3d-models/skull-3d-model.html
http://www.craftsmanspace.com/free-3d-models/piggy-bank-3d-model.html
http://www.craftsmanspace.com/free-3d-models/african-elephant-3d-model.html