Seems like the stud came out rather than the bolt. Very common issue. The way I did it on mine was to wire wheel the threads clean and then later used PB Blaster multiple times so the stud is nice and clean (was already clean and non-corroded but whatever). Loosened it with my 30 in" breaker bar and later zapped them out with my impact and stud stayed in place. Prep is key if you are OCD like me lol.