Then these people shouldn't be driving. If they are unable to put their foot on the correct pedal, what else aren't they doing?
"These people" are just anyone on a bad day. People make random mistakes when they do anything enough times.
I've had it happen. I was sitting weird and my foot just missed. You do these motions millions of times without thinking about it, so in that one-in-a-million case where something doesn't line up right, you get a very disorienting "why won't it slow down" feeling, and it's easy to panic. Your muscle memory instinctively pushes the "brake" harder to compensate, but it's actually the accelerator. It takes a moment for your brain to diagnose the situation and correct.
No harm done in my case: average car, open road, healthy and alert so I figured it out within a second. If I was in a Tesla Plaid, in a congested area, tired and distracted, I would have put it through a store window.
It was an eye-opening experience.
"I think trash is the most important manifestation of culture we have in my lifetime." - Johnny Legend