I don't know if auditing will answer your questions or help solve this problem, it seems that when opening the document directly from the shared resource, the server is encountering a critical error possibly involving the kernel.
I might first be tempted to load Dr. Watson on this server, and then duplicate the problem, after the server crashes and comes back up, you can view your event logs and the dr. watson log to get a more detailed idea of which process is interrupting server operations. Afterwards you can setup process monitoring and adjust server resources appropriately, OR...forward the Dr. Watson memory dump to microsoft for their assistance with this problem.
Auditing is there to enhance security procedures and maintain a record of who's accessing what...it cannot discern between processes running on the server though.
Additional questions to ask yourself...
Does this crash occur with only one document or any Word for Mac Document?
Does this crash occur from only one workstation or user account, or from any workstation or user account?
Good Luck...