Hi...
simple like this.. look at the replay about minute 10:40 switch your camera to the guy "Rafael Telefonica" look at him exiting a curv and taking the chicane to the straight in Fe Green Rev with Fox... is this a bug i dont hear any sound in the car and it seems to be starting the engine but with that you cant go faster... see at the revs... is this a cheat or something?

No he is just running out of fuel, on the user end everything is fine.... he still has fuel in and car runs fine, at your end you can tell if he is going to run out of fuel soon because of the stuttering (no cheat).