I wasn't able to find any problem in any of the modded bodyguard units so I decided to try the problem from a different angle.

I replaced all of my modified files (unit_prod, build_prod, & projectilestats) with the originals. I then cleared all of my building and unit queues and ended the turn; unfortunately, the CTD still occurred, and in the exact same manner as before.

Does this happen to offer any insight into the problem?