I don't believe cyclists have any other absolute obligations. It makes sense to ride with good "style", to adhere to the traffic laws (if only to avoid the expense of traffic fines). Treat all other road users with courtesy and insist on courtesy in return. Advocate for respect and room for cyclists on the road. All these things matter, and as a cyclist I try to do them; I don't believe they rise to the level of a moral obligation.
That brings us to the cyclist who rode into an elderly couple and knocked them down, The man escaped severe injuries, but the woman suffered serious fractures and succumbed to her injuries earlier this month. The cyclist fled the scene. Don't do this. Don't ride like this. Don't duck your responsibilities like this. Don't do it, not because it hurts the image of cyclists, not because it gives irresponsible pandering politicians an opening to call for restrictions on cyclists, but because it hurts people. It kills people. It kills vulnerable road users just like us, people we have a responsibility not to injure. Don't flee the scene because the law forbids you to do so; don't flee the scene because leaving another human being in the street, in pain, someone you injured is wrong. It's wrong when motorists do it, and using a two-wheeled human powered vehicle doesn't make it right.