Got the car back. They replaced part number CM5Z-10A757-A which is the "Drive Motor Battery Pack Disconnect Switch, Disable Switch, Switch Assembly" and the car runs OK now. Guess that was it! It's a $140 part, and they would probably charge a person $500 total if warranty didn't cover it. It was covered under the 8-year battery system warranty fortunately.
It is #3 in the image, a switch used to disconnect the High Voltage battery system. Weird it would just fail to open like that.
I got a lot of shoulder shrugs (we don't care, go away, don't ask us that, kinds of body language) from both the service advisor and the technician himself when I asked them both if they thought I should proactively do the TSB 20-2004 with it's CM5Z-9916A315-A High Voltage Lower Battery Connector Shield and spraying the big connector with Daubert Nox-Rust 7703-W (waxy, gooey sealant to keep water out). I may try to do it myself since it looks kinda easy actually, rather than paying those labor rates. ... The Ford company would prob tell me to go eff myself if I asked them, but I might try anyway to get them to pay for it like they did in FSA 16B02 a couple of years ago.
The paperwork on it says:
(PPT is Pinpoint Test, and BECM is Battery Energy Control Module computer)
"30321 Verified Concern.
Codes P0AA01, in PCM (powertrain control module computer).
Performed PPT E1 No E5 Yes Test BECM code P0A0A00 Performed PPT A1 Yes A2 Yes A5 Yes A6 Yes A7 Yes. Vehicle still won't start and has the same code. Performed PPT A again with the same results. Still won't start.
Bench-tested the CM5Z-10A757-A Disconnect Switch and it was found to be open (failed). Replaced Disconnect Switch with new one and now car starts OK. Cleared codes and retests good. Measured time for abnormal diagnostics and replacement of the switch is 2.2 hours labor.