I had to look up the 'PEBKAC' acronym, but I think you allude to the problem of human factors engineering. It's commonplace in aerospace, where safety-critical, time-sensitive decisions must be made, and humans are in the loop. I would extend this to autonomous driving systems, particularly when you expand the system boundaries beyond the car itself. Humans are part of that human-car-environment system, whether as pedestrians, passengers, or other drivers and we should give them consideration.
This specific problem is just as much a design flaw as it is a PEBCAC issue.
You have two very similar pedals that perform polar opposite functions right next to each other, and they are both operated by the same foot.
I'm surprised this isn't a bigger problem.