Someone bleeding in the street needs first aid and/or paramedics. Answering questions from a police officer won't get that person either. Your statement really reads like a non sequitur to me.

I think most people either don't realize or choose to ignore the fact that calling the police rarely prevents any crime. It can be effective if what you're seeking is retribution or revenge, but once you've been stabbed whether you heal or not doesn't really depend on whether you answer questions from the police.

The news from Ferguson is a reminder that bringing police into a situation can make many situations much worse for everyone. If I find you bleeding in the street I'll help you get medical care and if you want to go to the police that's your decision, not mine.

How would you help get medical care? In an emergency situation most people would call 911 and request an ambulance. The 911 operator would request details on the nature of the medical emergency so that the paramedics arrive on scene with more knowledge and an ability to respond faster, and so that you can be advised on how best to proceed while waiting for the paramedics to arrive. The operator may also send the police regardless of if they were requested or not.

They can send the police, sure. Doesn't mean I have to answer their questions.

This is a somewhat absurd argument because what I'd do ultimately depends on the circumstance. If I truly know nothing besides my own name and that I found this person bleeding, I would be wondering where my other memories went and if I were brain damaged.

In the general case, they aren't going to be sending detectives immediately to ask questions because someone called 911. Nor would I stay on the scene longer than I was medically needed to be there. But the "general case" is a useless fiction.

Parent comment said a guy called 911 and was assaulted for his trouble. I asked what to do instead. What's the non sequitur?

After you call 911, yes.