Strange car failure - everything says it is failed

[crhenkel]

SO, I have a 2013 BMW with xdrive and a N55 engine.
I know the front seal is leaking and throwing oil to the driver's side of the engine. It is on the belt and the alternator pulley and getting worse.
I know it will eventually throw the belt and I am gathering parts and doing the seal this weekend. I know the huge issues it can create.
Before I could get to the weekend, yesterday, the car started throwing a weird parking brake symbol and telling me the parking brake was malfunctioning.
It is the electric brake. The auto hold brake would just not actuate and it sent a brake failure message. Ok, just get home.
Then it started...went from e brake to abs brakes to 4x4 drive to transmission to seat belt system to stability system, and then to the analog gauges on the cluster all dropping to zero and not moving any more. Yes, I wanted to stop, but I was in the middle of nowhere.
Got to the edge of town and stopped in a parking lot and stopped.
Ran a scan with my phone on the car and had like 48 failure codes.
All pretty much said the same type of thing.
Low voltage, no communication, Can bus link stopped or broken, no response to signal, etc.
Tow truck arrived and car started to help get it on flat bed.
Got to my house and car would NOT start, but still had plenty of battery.
Scan showed it charging and at about 14.1 volts Car was at about 11.9 volts when I called tow truck. Different error messages and lights were coming and going while I tried to get out of the rural area I was in and get tot eh edge of town.
Without car starting we could not get it in neutral to even unload it off the flatbed truck. Very irritated.
This morning I went out and the car started right up and the codes were gone. Like nothing had ever happened. Wasn't giving it a chance for them to come back.
I drove it in to the driveway and parked it and took my truck to work.
Question.
With all the oil on the alternator and pulley...
Could this have been an issue with the alternator not charging or intermittently stopping and starting to spin?
I have seen a lot of cars start to throw ABS codes then more follow if the alternator goes bad and your battery drops below about 12.1 volts. All sorts of error lights show up at low voltage.
I did see the alternator charge the battery but I am wondering is with the oil mess if maybe the belt was slipping on the alternator pulley at times and not charging and other times it would catch and build voltage and so on?

Battery tests good, alternator did indeed move battery from 11.9 to 13.9 volts even after errors, but that was after car cooled down and sat for a while.
Got it home and it would not do anything not even start, but battery was good. Then this morning is started right back up.

Help, any ideas are appreciated, I am nowhere near a BMW dealer and my Indi shops are not really very good past basic service and repairs.
In most cases I know and do more on my BMW cars than they do.
Christopher

[tracer bullet]

Stay on the battery path. Not just it but cables and etc. as well. There was a recall on one of them you should look into.