Please excuse the long replay, but this person was modding on and off so I decided to start recording. You will see it as you keep watching the replay. I noticed the person doing this in a duel we were in earlier as well.
User= Hephaestus
Also, I did not notice any ping abnormalities so I did not take screenshots. It was a constant 20-26 ping.
http://www.filedropper.com/dmtpuaaapikuji20130908143211
PS. Later in the replay the person even admits to doing it... lol.