It's a game time decision for sure. I'm not saying I would do it, but I would consider it. It seems like the cops are going to proceed as if you are the guilty party regardless. I see the upside of walking away, I don't see the downside.
You will most likely have tunnel vision at the time. There will be witnesses that you don't see. And you won't be thinking very clearly due to the adrenalin.
There is a very significant downside -- it will be much harder for a defense attorney to argue self defense if you run away.