Method 1:

He marks the position of the fastener, and using the proper tool applies torque to the lower limit.

If the fastener moves, he fails the job.

Method 2:

He requires a special inspection at the time of the instalation.

Method 3:

He requires a fastener where the head breaks off at the proper torque.

As an engineer I would require #2 or #3 and so state on the plans and bid sheets.