Still the point is, The server should respond properly or else having cast timers would be pretty stupid if it doesn't actually do its job.
There was a video where the guy is out of the Landslide at 75% cast bar and still got hit~ Lazy to look it up, should be a few pages back.

Just pointing out the bad netcodes of this game. I Can dodge landslide 90% of the time same goes for WOTL. But when this problem strikes your pretty much screwed specially on stacking plumes lol.