Just going to throw my two cents in here...
I have noticed a lot of latency issues on the Crysis 2 Demo. I'll mow a guy down, but I'll die from him a second later. I'd like to point out that I only play on servers that I have a <50ms ping on, and this is still happening to me. I've also had issues with being shot through solid walls, even several solid walls, but that is a problem for another thread.
Where does the crouch killing play into all this? Well, if you crouch then your enemy will not see you crouch until the data has reached his computer. Even with my low latency, that is still around 100ms which is about 1/4 of an average kill time on Crysis 2. This means your enemy has a 100ms head start because he isn't being hit for that period of time. It's like the Matrix, except running in real time so you don't get all the cool effects.
So, in conclusion, it is not your imagination that you are getting owned. I try to avoid face to face battles because of easy kill tactics like these that take advantage of the game engine and network connection. I'd suggest running to the nearest LMG, ripping it off, and one-shotting everyone you see. Clearly the most enjoyable way to play.