It is meant for emergencies, so a ten tonne bus isnt going to move very far when the engine cuts out, and seeing as most are semi automatic there is no clutch to press. When you use the retarder to break, which is just electronics without using the normal brakes, it can be a jolt sometimes, just remember when you childishly press the emergency cut out that if an elderly person falls off the chair and cracks a hip, thats normally the beggining of the end for them. But dont worry, your totally in the right to be able to do this as you lost your temper with a bad driver.

It goes to show how some think its alright to endanger others, because a bad driver deserves it eh? Double standards and hypocrisy?
If you cant sort your loss of temper with adult and non dangerous means because your having a tantrum, you shouldnt be on the road.