Hmmm? If the alternator failed coz of coolant being on it, then I think it will dry out...
Otherwise, this sounds like something I've been saying a lot recently...and just learned a couple of weeks ago...ignition switch ...search it and radio. Evidently, a wonky ignition switch wrecks all sort of havoc around.
But for now, just hope it's the coolant.
That said, coolant might not dry out as quickly as water...so I'm thinking out loud a little here...and don't suggest you do this yet pending others' opinions, but I wonder about rinsing off alt with water...since we know it works when wet with water.
Also, got to say if you have a leaking coolant system, not good to drive...and for that hose, you might've risked way more than you wanted to save the cost of asking a friend for a favor or renting a cab.
But, since the car started, the battery still had enough power, then that's dictating your issues...even though it gets fed by the alt.
Try the cluster test or measure voltage on and off with multimeter s/b around 12 off and 14 on.
I'll bet she's fine in the a.m....but consider rinsing off with just water as I wonder whether the stuff in coolant might be allowing current to pass through it and messing things up...don't know...just thinking it might conduct better than water...also, you might try cleaning out the contact for the vr in case coolant seeped into it. Also, of course, coolant on belts isn't good either...so rinse those off with water too...coolant is very slippery and really not good on belts and lack of drive on the alt belt would also explain electrical issues.
Anyway, sleep well...she'll be fine in a.m...97% sure!
Doug