Well, that is an interesting link galtaforce. I must admit that if I had a car with brake override I'd be going out to the car park to try a few of these things. On my MKV GTI DSG, I did not experience at all what they're mentioning they could do in that article. Pretty much as soon as the foot was on the brake, the accelerator did nothing - maybe I was pressing too hard, maybe you need ESP turned off?
Either way, it kind of sounds strange that brake override is not "overriding" in their examples. They do mention that "Brake override is a software algorithm that gives the brakes precedence over the throttle if both are activated at once", but I mean, if they manage to 'fool' the brake override in all the cases that they've given, then I'd question how it would solve the unintended acceleration issue the manufacturers have been having.