I know this is an existing issue that the devs are still hunting down but I wanted to give a friendly reminder. It's been happening more and more to me lately and I don't even play all that much PvP, so I can only imagine how much it happens to the hardcore players.
This particular video is from before the patch but I just took another video today that hasn't finished uploading yet with the same exact issue. It keeps ruining my win streak and I'm very worried about the consequences this bug will have in Guild Wars. It's going to lead to a lot of frustration. Hopefully the devs can spend some more time tracking the cause of this issue now that 3.0 is out:
I'll update this post with the new video once it finishes uploading.