Buy a new bolt.

I intend to, just trying to figure out if it's something Ritchey would send a replacement for, or if I'd need to go buy one.. and if it's safe to ride on in the meantime.

Your torque wrench is broken....

Do you drop/rough it on occasion?
When did you have it calibrated/tested last?

The early versions of this stem came with hex bolts that were replaced by newer torx ones due to premature failure.
Email Ritchey and they will ship out a new set of bolts for you.

If you somehow managed to break a torx one, then learn how to wrench before you touch your bike again.
These stems need very little bolt torque to hold securely.