This seems to be an incredibly popular belief despite the fact that there's no evidence for it and it wouldn't make any sense.

Waymo's remote support teams can reach into the driver's model of the world to fix things, for example maybe it mistook this stray traffic cone for actual roadworks - but they can't actually drive the car.

If Waymo needs a human to drive the car, they send a human to physically sit in it and drive the car. They have a whole bunch of people for that role. If you were in a Waymo that drove somewhere and there wasn't anybody in the driving seat, that's not because some 10 year old was using a PS4 controller to steer it from Bangalore, that's the Waymo driver software.