This happened to me too (toyota minivan). I was in stop-and-go traffic and went from accelerator to brake, and the vehicle started revving it's engine to try

This happened to me too (toyota minivan). I was in stop-and-go traffic and went from accelerator to brake, and the vehicle started revving it's engine to try accelerating. (gears were grinding trying to shift to compensate for the slammed brake). The situation ended when i lifted my foot off the brake and pumped it. I took it to the toyota service and they said it was due to me pressing both brake and accelerator at the same time. I was skeptical of my own user-error, so I later tried to recreate the issue (by pressing brake+accelerator together in various combinations) but was unable to repro it. Now that I see this article, it makes me realize it's probably the firmware.