Ok. The weirdest thing just happened while I was playing in U13 CTF Public (It resulted in a ban... they thought I was hacking, but I was recording a demo for reference).
The previous round had just finished, and everything was fine, until the new map started and I spawned (b2b if anyone's wondering). I started to run down the slope, and I started popping around, like other people do when they're lagging, but it was on my screen.
What's more, the soldier I was controlling was not me. He looked different, like a normal soldier, with plainer colours.
Now for the amusing(?) part. There was another me, which was all my colours, so evidently I was controlling the wrong soldier. But the really strange thing was that the real me followed almost every movement I made. I tried running around, jumping, shooting, jetting... and the real me followed everything I did.
Eventually someone did a vote kick, assuming i was hacking (which, I must admit, it does look rather like). So I tried to explain what was going on, but nothing I typed would appear in the chat area. So I stopped the demo, left the game, and tried to rejoin, hoping that would solve the problem.
Well, it probably would have... but... "You have been banned on this server."
I uploaded the demo, so you can see it for yourself. It looks very similar to what I saw on my screen, and you can see what's going on.
edit: I just tried again... I'm not banned anymore... and the bug is gone