Not sure what you mean by full ABS stops?If we take the report as completely true, then we can go further and say there must be a fault with the hydraulic brakes. Working normally the mechanical brakes alone in a car should be able to override the motors (regardless of how software may be inappropriately requesting motor torque).
And ABS didn't engage per the report so that rules out some weird oil spill or slick surface as the sole cause.
Post incident have you tried any full ABS stops from 20-30 mph? Do they feel normal?
I haven't had a scenario where I would need ABS to engage like stopping short in the rain or anything. Braking has felt completely normal since "the incident". We had a week of storming here recently but don't think the ABS engaged at any time. I usually drive in a manner that lets regen do most of the braking. I don't often need to brake hard.