Interesting. So, would you advise—if you do want to give a witness statement, because, say, someone close to you was attacked—just telling the officer (in not so many words) to go away; and then, later, writing out a witness statement and bringing it down to a police station?
Depending on the exigency of the circumstances I would definitely suggest not giving a verbal statement, and preferably consult a lawyer before giving any statement whatsoever to the police.
If your friend's life is at risk or in danger, you may not have some of these options and would have to make a judgement call at that time.
I personally would do almost anything to protect someone I cared without regard to the risk to myself.
See, that's the thing, though; I see this kind of weighted decision-tree logic as only being applicable exactly when the situation has dire risks on both sides.
Disregarding risk when someone you care about is in danger, is exactly how people end up with charges pinned on them, no? If you, concerned about a missing friend, talk to police about how you were likely the last person to see them, then if they turn up dead, you might to blame.
It's important exactly for these cases to be able to know what you should do, and how to do it properly, in order to be able to do the most to help those you love, with the least risk. Not to say "never"; not to say "screw it, this time's different, tell them everything"; but to know the precise shape of the middle path you must tread.
