Nobody can tell by looking at me whether I've just stepped into the woods for the first time, or if I'm a veteran hiker. We can make some assumptions based on clothing and equipment, but that's all they are, assumptions. Furthermore, no matter how many miles I've walked, I don't know everything.
More than once we've had discussions about somebody doing something questionable or dangerous, maybe LNT violations, or starting a trail late in the day with no visible equipment (no flashlight?) and perhaps with children in the group. If a tragedy occurs, nobody gets scolded for giving unsolicited advice. Rather, the worry is that perhaps we didn't say enough.