Consider that there are "pages" in a horizontal ListView and each page is vertically flickable. This is a common structure for mobile applications. Swiping (using two fingers in Mac) a vertical page is very difficult since it tends to switch to horizontal neighbor pages. See the attached test app & video.

The problem is very easy to reproduce on Mac (vertical & horizontal wheel events), but some have reproduced the problem even using a normal mouse. So perhaps some logic is needed to exclude flicking both directions the same time...