Another parkour hacker.. his user name is js25000js25000 Here is some evidence, I forgot to record so I just took screenshots :P 3 pics for ya here:
What also supports this thread is that back when this person hacked, level 4 was griefed and nobody could go further than where Arv is standing. Even if that guy fell, he wouldn't be back there.
Still photos are insufficient evidence. The server lags in many different ways. Video is only way sorry.