Jealous?

Many of you will be familiar with this scenario.  Guy A ("Clark") is friends with (and sort of likes) Girl A ("Chloe"), but Girl A is dating Guy B ("Ian").  Clark is a genuinely good person, and suspects that Ian isn't that great of a guy.  Being a good friend, he brings this up with Chloe.

Let's see how this plays out.

Clark:  Hey, Chloe, I wanted to talk to you about something.
Chloe: Sure; what's up?
Clark: Well, it's about Ian.
[Chloe becomes suddenly suspicious.  Her eyes narrow, and she slightly frowns.]
Clark: I don't think he's that great of a guy.
[Chloe becomes defensive and irritated]
Chloe: Why would you say something like that?
Clark: I heard him talking to some of his other friends about "some girl," and not in a really nice way.
Chloe: And, what? You think he was talking about me?  Come on, Clark; have you never said anything stupid just to impress your "bros?"
Clark: No, I haven't, and--
Chloe: Oh, that's right, because you're SO PERFECT.  Y'know what, Clark? It's not your business who I date.
Clark: No, that's not the point. I was just concerned for you!
Chloe: So making judgments about the guys I like is being "concerned?"  The world doesn't revolve around you!
Clark: Hey! I was just trying to make sure you didn't get hurt!
Chloe [firmly]: That's not your job, Clark. Leave me alone.

Chloe assumes that Clark is jealous, which he very well may be. However, Clark is, of course, correct in his assumption, and Chloe ends up being hurt.

Now, here's the question:
Was it right for Clark to say something in the first place?  After all, it was technically "not his business," but he acted out of concern for his friend's well-being.
It's true that Chloe probably would never have changed her mind about Ian, no matter what Clark said.  There was no way for Clark to do or say anything without being labeled "the bad guy."

I have been "Clark" many times before.  And I always will be.

Now, I don't always bring up the issue.  Sometimes I think that the girl in question is capable of figuring her current beau out for herself, so I leave her to do that.  However, that is often not the case.

No matter what, I am not going to just shut up and sit idly by when I have think that someone I care about is going to be hurt.
Girls, do me a favor and give me the benefit of a doubt, okay?