I would consider myself somewhat of an expert on how accurately men describe their height. Once upon a time,I spent eight years in the tuxedo business. We asked men for their height and weight before we measured them for their tux. Some men give their accurate height, but quite a few exaggerate, even when estimating their buddy's height!
My experience with the ones who do exaggerate is that they often add up to 2" and a few add 3 or 4". My standard reply to a man who was clearly stretching it was, "So, would you like to rent a tux that fits someone who is 6'1", or would you rather have one that looks perfect on you?" (You have to smile just right to get away with it, but it works!)
I wish men weren't so hung up on height. I have noticed many an attractive young man in my day, short, tall and in between!
Depending upon a person's build, height can be very hard to accurately estimate without giving the person a really close look. A man walking down the street at night from a distance...unless he happened to be walking right in from of a six foot fence or other point of reference, I'd give or take four inches on a witness description.
MOO