I was in the arena because people were fighting, and I like watching people pvp. I noticed he was a bit fast, and I saw him "jump" rather high a few times, so I jumped in to get proof of him cheating. Weather he was flying or not, I don't know. I don't have proof of that. What I DO have, is proof of him speedhacking.
Skip to 1:30 and watch till 1:40 for the main point, it was so laggy that I couldn't get any more footage of him doing it. Sorry the video is so long, I didn't wanna die, and I had a non-stop flood of people trying to kill me.