Well, let me say again that I don't support what the cop said, but to address one specific question:
And yes, perhaps next time he would keep his opinions to himself instead of influencing someone else into buying a whistle instead of a handgun...you can't possibly think THAT is a good idea.
Honestly, sometimes I think that is true. Maybe not a whistle or a noisemaker, but I think there are plenty of people out there that have no business carrying a gun. I am not arguing about their right to do so, instead I am arguing that there are people that buy a gun, never shoot a round through it, don't do things like go to a basic pistol course, aren't particularly safe, and don't carry in such a way as to give themselves immediate access. Could a gun have prevented this murder? Absolutely it could have. Could she have gotten murdered even if she had a gun? Absolutely.
To give you an example of what I am talking about, I give you my mom. My mom carries a Ruger revolver in her glovebox wrapped in a sock. She has never fired it, and honestly, with her arthritis, she has no business practicing with either .357 of .38 special loads. She hasn't shot any sort of handgun in probably 20 years. Put bluntly, there isn't a chance in the world that that gun is going to alter my mom's ability to keep from getting murdered. What might keep her from getting murdered (notice, I say "might") is the fact that she hauls around pepper spray, a cell phone and a rape whistle. Fact is, my mom is never going to carry a pistol nor is she going to regularly practice, regardless of the fact that I harp on her constantly about it. Her desire to keep a pistol on her person at all times is about the same as my desire to become a ballet dancer.
Does that mean that my mom is setting herself up to be a victim? Compared to Clint Smith, yes. Compared to a whole lot of other women, no. I don't think that the detective had any place saying what he did, but neither is he wholly incorrect in his advice. Maybe if your daughters friend would have had pepper-spray, she would still be alive today, but that statement is just as true for a gun. Frankly, if you don't have the mindset to use it, a gun is about as useful as a lead pipe.
Now, just to be clear, let me say for a third time that I don't agree with what the detective said. Your advice to your kid was, in my opinion, good advice. It doesn't change my opinion that just letting things drop at that point was the best thing to do, as you can talk to your kid after he leaves. Just remember that simply having a gun isn't the answer. Practice, availability, mindset and situational awareness are all absolutely necessary to make having a gun useful for defense.
Edit to add: What I REALLY disagree with is that the cop said she might have been disarmed and killed with her gun. Aside from the mostly philosophical points I have made, I hate the idea that this cop was essentially saying that fighting back is the wrong move, particularly given that she was in fact killed. For all that I just said about my mom, the one thing that she absolutely has going for her is that she will not just meekly roll over and let someone rob her or whatever. All citizens in general and women in particular need to get past this pansy idea that fighting back is somehow the worst possible choice. Dang it, if someone steps into your perimeter, you should fight with everything you have. A person that resists is much less likely to be a victim than one that simply rolls over and hopes for the best, at least in my opinion.