Haha, yes, I remain skeptical at best of QI. I know just enough physics that I probably should have thought of the issue you mentioned up there, too. Still, the idea remains pretty enough that it's tempting to try to salvage it, like even if it's not technically Unruh radiation, maybe there's a reference frame or other perspective where the math works anyway... But that only makes sense if the real life numbers work out, and I'm not going to take this guy's word for it.