I'm not saying he didn't, but when dealing with consumers (as opposed to mechanics & trades people) you have to generally assume that when they say 'I measured and it was 2"' that means it actually measured 2", not that it was 2.375" and nominally 2".

It really gets bad when you get into situations which mix plumbing sizes and HVAC sizes. For example, a 1/8" threaded by 1/4" flare ell . . . is the same pipe or tubing size on both sides of the ell! Because years ago, I did mechanical repairs for a variety of full service restaurants and bars in Chattanooga, I was always into projects with mixed sizes like that. (I was licensed as a master plumber.)