If you moved on your screen in time and still got hit and this doesn't happen in any other game aside from ARR then it's really just the game's bad netcode, the devs themselves have acknowledged the delay being by design as a way to reduce stress on the servers, don't let anyone fool you into thinking it's all your fault because they're usually bad players themselves.

The devs do know about it though and have said they're trying to fix it in 2.1 but only in certain high level instances and not in the open world, it remains to be seen in how many instances and how big of an impact it'll have for people having issues.