You could possibly use this forum as a reference. that is to say, explain that this is a forum full of people who will not tolerate cheating (if you want examples of what has happened when people have been caught in the act just ask any one of the old guys), many of whom are or have been entirely dedicated to finding every trick the game has to offer within the bounds of what is "legal". Also this forum is trusted by, and indeed has members from, the wipeout dev teams.

also there is plenty of filmed evidence on youtube both of "impossible" race times (PAH!) and of latency issues and lag, for reference: "impossible race times" Small but noticable latency issues of exactly the kind they mentioned