I’ve only seen the PA animation once on Phoenix and that was in a duel vs. a realm mate.
What happens for me when I get perfed is the assassin is just standing there in combat mode. No sound, no animation— just me losing about 40% life. I only saw this type of thing happen on live when the perf damage was lethal. The first few times it happened to me here I was moving around and in combat with other people and just assumed they messed up their opener because they were standing around in combat mode. I have always had a chance to slam before the CD though. Haven’t seen what you’re reporting.
Something is definitely wrong with it, and if there isn’t a post on the tracker I’ll make one.