Looks like there was no way in hell that nut was coming off.... probably a good thing that it broke off for you...
I had to take mine off when I swapped by exhaust a few weeks ago.... I left it on the exhaust until I had to off the car... wasn't quite as bad as yours and was salvageable but I had to use heat to get the nut off...
Dinan CAI &Throttle body, ESS Tuning TS2, Bimmerbrakes gen3 headers, UUC SSK & DSSR. Achilles oil pump, VAC oil pan baffle
M3 Motor mounts, UUC Trans mounts, Modified clutch style LSD 3.15, TMS front subframe reinforcement, Koni Yellow sports,
H&R sport springs, UUC sway bars, BMW Perf. Rotors, UUC SS brake lines, Hawk HPS pads, CSL replica wheels,
Rotora strut bar, FXR HID conversion, M3 Mirror conversion, BSW stage 1 speakers