Sometimes the confusion isn't in the fit or terminology, it's in the location. I used to work out at a gym that helped people keep goals by tracking their weight, measurements, workout levels, etc. When I went for a weigh & measure, what I considered my waist and what they considered my waist were two totally different areas on my body. I had the same problem with my mother-in-law - she asked me to adjust a skirt waistband, so I measured her and adjusted it. Problem was, she wanted to wear that skirt a lot higher than I had adjusted it for, so it didn't fit the way she wanted it to.
I have a hard time finding jeans that fit correctly - the waist is always far too high on me and I end up with a baggy crotch, even though I am long-waisted. I usually end up wearing a belt and rolling the waist up over it. Makes me wonder how those pants fit the poor creatures with short waists.