Yes, a surge protector that included a circuit analyzer would have picked up on the problem. I'm currently using Surge Guard Model 44260 which monitors open ground, open neutral, reverse polarity, and has surge protection. A bit spendy at $85 but worth it if it protects me and my rv equipment.
2015 Greyhawk 29MV
Honda CRV toad with Blue Ox baseplate
Ready Brute Elite towbar with braking system
TST 507 Flowthru TPMS