Being a "drunk driver" can range from someone having had half a pint in the pub with their dinner at lunchtime, to being absolutely twatted. While talking on the phone provides a distraction, it does not directly affect reaction times or judgement. Give someone 10 pints, and I would bet my right bollock that my little sister could drive better than them, on the phone.
Pengwuino, I suspect that far many more drivers are prepared to drive whilst talking on the phone, than drunk. This would explain the numbers in your city.
In addition, I do not believe the mythbusters test to be trustworthy. I'm assuming that the participants had been briefed on what they were actually doing? What criteria were they tested on? Reaction times? Maintaining control of the vehicle?
Given the choice, I'd much rather step off the pavement into the path of a driver who was talking on their phone, than someone who had drunk as little as 2 pints.