I've made this post before.
When someone is telling you about an unpleasant confrontation—an encounter with a hostile stranger, an argument with a friend or family member, contemptuous treatment by their boss, rude and uncaring customer (dis)service, whatever—there are several acceptable responses.
"That's terrible, and I hope it doesn't happen again." "Are you okay? Is there anything I can do to help?" Even a simple "I'm sorry." These are all fine things to say, as long as they're sincere.
Unless they are specifically asking for advice, it is *never* advisable to say, "Well, what *I* would have done is ..." Just don't. The instant you feel those words start to form in your mouth or on your keyboard, stop. It is better to stay silent and be thought a fool, than to speak and remove all doubt.
First of all, you're not them. What you would have done is completely irrelevant. They may not want to do what you'd have done, they may not be able to do what you'd have done, or they may believe that what you (say you) would have done would only make the situation worse.
Second, it's really easy to be a chest-thumper or a keyboard warrior. "What I would have done" in your imagination might be exactly what you'd have done in that moment—but let's face it, probably not.
I spend more time than I probably should thinking about what I *wish* I'd done in a lot of situations (some confrontational, some not) and I know I just wasn't witty or brave or quick-thinking enough to do it. If I can't live up to my own standards, I sure as hell don't get to impose those standards on other people.
Third, ask yourself honestly if "what I would have done" has ever helped *you*. I guarantee someone's said it to you, probably more than once. Did it make you feel better? Give you a useful strategy the next time something like that occurred? Strike you as clever or wise? I bet I know the answer.
BTW, yesterday someone made a credible threat to kill me. What I'd have done if I'd had time to think about it was ... exactly what I did: drive away. Fortunately I had that option. What anyone else would have done, I really don't want to hear.