There are times when just putting your hand up and apologising is the right decision.
OK, if you are talking on your phone and fiddling with your ipod and riding with no hands and you run into an old lady and knock over her shopping, yes, apologise, and admit it was your fault. But in other, murkier situations (for example, the situation laid out in the post that started this thread), it's not that simple.
I am a bit confused as to why this is controversial. Nowhere did I say that anyone should leave the scene of an accident, and I certainly didn't say that anyone should try to blame others for the accident. Just make sure everyone is safe, share information as needed, and wait for the police or emergency services if they are coming. If anyone tries to start a conversation about who is at fault, just smile and say 'we can worry about that once we're sure everyone is safe' or 'it's hard to know exactly what happened, and we're all a little shaken up at the moment, we'll let the police and/or the insurers sort out who's at fault'. It's not rocket science. It's what I would do, and it's what your insurance company would expect you to do, but of course you are free to make your own decisions and accept the consequences.