Some pvp places you can hit people out of the map or into places they shouldn't be.
For example, a few days ago, I was fighting baddies on pyrat bay. I went in the tent, a pirate hit me on top of the counter, I couldn't get off the counter. Then, it hit me again and I was knocked behind the counter (Not supposed to be there). I had to wait a little bit to get warped away because unstick me wouldn't appear.