On thing I do to meet my own personal standards, as well as regulatory requirements, is following the safety briefing I give my passengers (GA flying), I look at them, and ask them if they have any questions, and, I wait for their answer.
The written report of the passenger casts an already non standard operation to look less good. For those times I've been flying a non standard airplane (like cabin survey equipment installed, which could impede exit, I've been extra vigilant to assure everyone aboard was comfortable with their personal exit plan.
Speaking of seat belts, some very old designs (found on Cessnas of the 1950's vintage) were simply aluminum cam buckle, which engaged the webbing of the other lap belt directly, with no second (metal to metal) buckle tang. I hope these are not the "old military" that the passenger describes. That type of cam on webbing were AD'd out of all Canadian airplanes decades ago. Not only were they very hard to open if they had sustained a load, they were impossible to open if they had sustained a load and were, or got wet, or you were hanging from the lap belt.
Yes, passengers bear some responsibility for understanding a briefing, or asking for clarification, and thereafter doing as briefed, but they are always entitled to a briefing, and opportunity to ask questions they may have. Any pilot who does not assure this has taken place makes us all look bad.