Vayne Condem Bug?

I don't know if this is a bug or working as intended but it always seemed very off to me.

In more than one game I've been playing against a vayne and needed to jump over a wall such as Shyvana's ult or Sejuani's or Vi's Q. In rare instances, Vayne has condemned me and stunned me on the far side of the wall. I've been hit by Condem and reached an edge of a wall, however, I haven't been pinned to a wall, as per the spell, but happen to be passing through a wall edge on the far side.

I'm not sure this is a bug or working as tended but everyone time it's happened to me it's really bugged me.