Citadel bug or server sync issue?

Obvious character de-sync and animation bugs almost cost me another citadel (video shows character displacement, boss only have 59% freeze build up but already frozen, near death blood comet later with no time to respond)

Assuming this aspect of endgame doesn't change for 0.5, GGG needs to look at the citadel bosses VERY CLOSELY (either bugged fight or server sync issue) - Doryani post death lightning attack is well known, and now this - it's already hard enough to find citadels in the first place, I'm hoping they take another look at this in 0.5

Let me know if you all have also experienced such things