Is there any way to check an SIR coil to confirm that it's bad?

During the engine swap I had no idea about the "don't spin the steering wheel when shaft is disconnected deal" (i haven't had my steering shaft cover on in years), and I guess myself or someone spun the steering wheel a few too many times.. oops.

What actually breaks? Can I test something to see what it is?

 

The coil contains a wiring harness that only has enough slack to cover the normal rotation of the steering wheel. Most likely you could perform a continuity test of the harness; Shoebox may have an electrical diagram on his site.