Luck smiled on you! While it's not the worst job in the world, replacing a broken hub stud can be a bit of a kick in the nut.
Good new gents, stud seems to be fine. The old nut was stripped. Seems like a PO might have had some hardware store bits on there. I preemptively ordered a new stud so at least I'll have a spare on hand.
I order nuts and washers in bulk so I'll never hesitate to throw one out if I don't think it's up to the job. Also, you'll find that quality parts in bulk are significantly cheaper than the hardware store, too.