Cyclist kills motorist

I agree, punching someone is clearly very deliberate, whereas dooring someone is clearly a result of not paying attention to what you are doing.

If not paying attention to what you are doing results in someones death then that's clearly a bad thing, but in the (entirely theoretical) case of "death by dooring" I reckon the driver of the car would get off without any real sanction.

This is based on nothing but my prejudice, that said.

I guess it becomes a question of what you believe prison is for. Is it there to rehabilitate or is it there to punish (or, as we see more and more in both the UK and the US, is it there to get people who are deemed socially problematic off the streets and out of our minds)?

I can imagine someone accidentally killing a cyclist by dooring them, and a prison term being the least of their worries. Having to live with that guilt for the rest of their life would probably be pretty shitty.