Btw, there have also been Prius recalls due to faulty ABS software, so while you'll probably always have some control, braking action can certainly be affected by software issues.
Also hitting the wrong pedal is not exactly uncommon. People don't like to admit they just made a mistake, hence claims of "unintended acceleration". But just like the claims against Audi back in the day, the modern claims against Toyota appear to be unsubstantiated.
Some people might be unwilling to admit that they stepped on the wrong pedal, but the likelyhood that some random HNer would do that and then make a post about it?
ABS brakes work by relieving _or_ reinforcing brake pressure, so depending on the system you could end up with uneven, little or no braking action after a failure. Or you could end up with locked wheels.
And I don't think HNers are somehow less likely to hit the wrong pedal or refuse to admit it. There's always that possibility that they don't even know they hit the wrong pedal.
..and the 400% increase of unintended acceleration events (from the testimony) starting in 2004 is also a complete accident, or brought on by some witchhunt?
Aren't you stretching the limits of what is a reasonable assumption in order to maintain that opinion?