You'll find that most companies only take 1 measurement. That's from the base model with the full metal panel. They usually don't bother re-measuring for the panel with the acrylic window, nor even for the TG version. All of which can and do have real distance differences of several mm.
And then there's some companies who will set a safe limit. Can be 5mm or more at times. So there might be a real distance of 165mm, but a claimed distance of only 160mm coolers.
Some cases are just plain mental. It's documented 1 case in particular has max cooler height of 152mm, yet there are multiple posts showing pictures of that case. With a CM hyper212 evo installed.
There's also case error. My CM 690 II Advanced had a definite warp on the side panel, clearly visibly concave. Took a little rubbing, but got that flattened out.
Best advice I can give is leave room. I'd not choose a 160mm tall cooler to fit in a case with 160mm of clearance. That's just asking for complications.
In an ATX mid tower, you shouldn't have to have issues worrying about mm differences, that's a measurement typically reserved for mITX SFF builds.