Until I saw the CR video, I always believed that brakes were always capable of overpowering the engine. But what the video showed was EXACTLY what several of the people who filed complaints with NHTSA said happened to them - the engine overpowered the brakes and if they tried to pump them, they lost all braking power. That last part mystifies me, but seems to be true nonetheless.
When I had my Prius, I became familiar with how in that car, if you hit a pot hole while braking, the braking force went away for an instant. While it never placed me in jeopardy, it was unnerving the first time it happened. Toyota has offered the explanation that it takes a short while for the vehicle's computer to transition from regenerative braking to actual braking. Well, that is just goofy. What that means is that in the Prius, when you step on the brakes, a computer reads how hard you are pushing and if it calculates that the rate of deceleration you want can be achieved solely by the "drag" caused by the electric motor being used to generate electricity, the system prevents the brake pads from actually doing ANYTHING unless and until you send a signal that you want more braking by pressing harder on the brake pedal.
What I learned from all this is that I really don't want my car thinking for me. Yeah, I understand that the EFI system is not something I want to be personally involved in, but dammit! When I step on the brake pedal, I expect the brake pads to make actual contact with the rotors NOW, not at some yet to be determined time in the future. In addition, the Prius had a Vehicle Control System that, as I understand it, could theoretically apply power to a driven wheel of its own accord if it felt it would help avoid a spin. That is too much electronic intervention for me.
I'm glad I have my 73 MGB. Now THERE'S a car that does only what you tell it to do and nothing more!