Ya the charge -> stop -> charge is actually lag as far as I can figure. Think about how fast you are moving and how quickly that movement has to go to the server, and such. It does this when I lag, and it happens quite a bit to me in games. It will definitely happen if you are in the yellow and maybe happen if you are the low green. The only solution is not to sword charge.

The worst is when you charge, and you do an uppercut swing. There is a buzzing sound from when the sword hits things(no walls), and then the person just doesn't die.