Also, if the reports are true of the make/model of car, that thing is ridiculously overpowered and can get to insane speeds in a very short period of time.
That said, there is taking the foot off the pedal. Anything is possible, but stuck open throttle would be my uneducated guess. Extreme intoxication the second guess.
It's surprisingly common for people to hit the gas as hard as they can, when faced with an unexpected event - all the time believing that their foot is on the brake, and that they need to push harder because the car doesn't seem to be slowing at all.
I wouldn't say it was common, but it happens. The trouble is, the video doesn't seem to show that there was anything that warranted a reaction.
The video is brief, but the car is going that speed right away once on camera and at no point does it appear to veer or apply the brakes. It could simply be driver error. Most accidents are. But having been there several times, feels like something else caused the problem.