True, though I would not normally recommend someone to shut off their engine as it cuts power steering and possibly impairs hydraulic braking.
I'd always recommend anyone turn the engine off rather than keep accelerating. That's a no-brainer. First, I'd tell them to put it in neutral...if that didn't work, cut it off.
Plus, you'll still have brakes and steering with the engine off....just not power. I'd much rather worry about that than about the car running away.
Honestly, if you KNEW your accelerator was truly stuck, you CAN use the brakes to haul the car down to a stop. The catch is, you have to do it the first time you try braking...you can't sit there and slow it down some, then let it speed up, then back down.....do that and you'll get brake fade.
But on the Lexus that ran away with the cop driving it, the brakes would have stopped the car, had he gone ahead and tried to do so to begin with. Of course, that's easy to say in hindsight, but anyone else it happens to should remember that.