Your firs para: could you imagine the situation where you tell a parent that you called the police because you were worried about their child? That's not an easy conversation.
I agree that people should report early and report often; and allow experts to make decisions. Sadly, reporting early and often just swamps people who are already far too busy dealing with children who are being abused, or it dumps reports with police who take action when they don't need to do anything more than have a chat.
I agree it's not an easy conversation, but if you think it's important enough to take photographs and call the police about it was important enough to communicate to the person who you have made a potential suspect. In this case it would probably have resulted in a much less traumatic outcome for the author of the story, who at worst might have missed her plane.
I agree that people should report early and report often; and allow experts to make decisions. Sadly, reporting early and often just swamps people who are already far too busy dealing with children who are being abused, or it dumps reports with police who take action when they don't need to do anything more than have a chat.