ThatBloodyWoman - in one post you state 'there was no accident' - how is it not an accident if your dh could not stop in time to avoid 'gliding into' aka hitting the car in front?
And I understand why he was so keen to avoid sudden braking, but surely, then, he should have been leaving bigger stopping distances, to avoid a situation such as the one which arose. He did not do so, and because of this, he could not stop in time, and therefore is responsible for what happened (the impact) though if the other driver did something stupid/ careless/illegal, then he has some moral responsibility for what happened.
When I had the accident I described this morning, I was apologising to everyone around, even though I had done nothing wrong at all - I was faced with an emergency (the exhaust from the car in front bouncing down the carriageway towards me), and had no choice but to stop (swerving would have put me in the path of other traffic, and would have made them swerve or, possibly, crash), and it wasn't my fault that the second van behind me in the traffic hadn't left enough stopping distance, so hit the van in front of him.
The police confirmed I did the only sensible thing - but I was still apologising, due to the shock.