I am frequently experiencing that it shows no animation when reloading the gun, the clip just disappears and after a while a new one appears. The gun reloads fine, and I get the "New magazine is full" message, but it just doesn't show the actual first person animation.
If I have observed correctly it only happens when my avatar is standing up, not when he is crouching or prone (although it may have happened and I just haven't been observant enough).