Take the anecdote of the person to whom you replied. Lots of people will tell that person's friend, "oh, just let it go, the border agent didn't really mean anything." And if the person complains to a higher authority, the complaint is staggeringly likely to get brushed off, if not used in exactly the opposite way the person intended when filing it.
At a previous job of mine, I worked for the phone-based customer service while another team in the same group operated service windows for in-person assistance. No authority here at all, just answering questions. More often than not, if someone filed a complaint about how one of our window clerks had treated them, the supervisor delivering the complaint to the clerk treated it as a joke. "Well, it says here you told the woman she should smile more. I pulled the security tape and she was pretty cute. Sure would have looked nicer if she had smiled, yeah?" Yeah boss, sure would have! "Darn right, can't fault you there, so we'll just toss this one as unwarranted, yeah?"