Anyone have an overcharging alternator fry a battery?

It's either the VR or a short of some kind is causing the rotor to "full field." Depending on how it is wired, it could be a short IN the rotor. In any case START by repairing or replacing the alternator. Go from there. As the battery has been boiled it is likely bad.

Nothing to do with this here problem, I do NOT like "one wire" sysems, because they require a vastly oversize charge wire.