Exactly what quinch said. Latency issue from either you're end or Ubisoft's. Do a speedtest and see what you're ping as well as download and upload speeds are. This should tell you if it's on your end: http://www.speedtest.net/Sounds significantly like a lag/latency issue. This could be either due to your connection speed (are you being "throttled" by your provider during peak times?) or server lag due to heavy server load from players.
I would say this is an intermittent issue for you and not really easy to fix whilst in-game. I usually stop playing and restart my server or just log out of the game and back in (so I get an alternative game server).
You'll often see oddities like this and characters "sliding" instead of running, or players firing over cover whilst still in the fully hidden pose etc. Its just a delay between the information from you to the game servers and back.