I think that is rubbish, and that: 
 
At first, the chance of picking the car is 1/3. 
 
once a door has been opened the choices are narrowed to 1/2. 
 
no matter what the first chosen door is, the other goat will always be shown, leaving 2 doors, one of which is a car. 
 
Therefore I believe it doesn't matter if the contestant switches as the probability is 50/50.