there's always a possibility of an incident when driving - even when sober - so saying that driving high reduced the chance of your having an accident by 100% (i.e. to zero) is laughable nonsense.Not to dispute what etarded is saying, but just to point out that nothing is black and white:
there are times when smoking weed improved my driving, reducing the chance of an accident by 100%.
as ever, the onion nails it: "don't get drunk and drive. disregard this if you happen to be one of those people who drive better drunk."

related reading:
Thoughts on the "I Drive Better High" principle
Does cannabis make a difference to your reaction time?
alasdair