You can and you should! Carpooling in a very gas efficient car compares favorably to biking with the most CO2 intensive diet. Biking wins in all other cases. Also, if you don't eat an additional calorie for every one you burn while biking — I know I tend to burn off winter weight when biking around in the summer — these calculations are less applicable.
The article didn't mention a lot of other factors. If you drive to work you might go to the gym after work to burn the same calories the cyclist burned. Then you'd consume the same extra calories he did. Not only that, but the cyclist wouldn't have to go to the gym so they wouldn't even put in those miles.