Don't worry about falling when stopping, worry about falling when starting. Make sure you're in a low enough gear to get started and pedal a couple of revolutions with only the clipped in foot before you can get the other foot clipped in. The bottoms of cycling shoes tend to be slick and if you try to pedal with the non clipped in foot, it will slip off the pedal, you'll lose momentum, and fall over very slowly. Let me tell you, it's embarrassing! Sheesh, would it kill them to put a non-slip surface on the bottoms of the shoes????