Wombat,
I have an old compound miter saw that when I first bought it, it would stop when you released the switch. Sparta flew and it was real loud every time it stopped and it kicked upwards from the torque. One day instead of stopping, it ran backwards and I could not turn it off. I had to pull the plug. I worked on it and got it working again. After a few times of this, I disabled the reverse kick and it has been working for the last decade with no troubles. It just does not stop on a dime.
Jim