Ha ha, very funny. The push-back crew have the control and responsibility. Having said that, if ATC request that the push-back be stopped, it is normally the flight-crew who get the message, and pass it to the tug driver. At some airfields the tug is in direct contact with ATC. During the push the crew don't touch the brakes. A brake application would, at best break the weak link in the towbar, at worst caue damage to the nose leg.