I've done Prevent training twice, the second time was easier because I knew what to expect. There are situations in life where you know in your heart, that anything sincere you say about it will just create a disaster. So you say as little as possible, answer direct questions simply and politely whenever necessary, and generally avoid saying anything that could be considered negative, controversial or (worst), unhelpful.
Prevent training is that, hours of it. Give me a speed awareness course any day.