Playtime doesn't matter. He/she may have been playing offline mode throughout his journey. Using a speedhack is obvious by how the truck moves. I do not think that any of the participants used any. I've seen a lot of speed hackers, and trust me, none of this influenced the race. Keep in mind that turning and such movements, and gameplay fps affects the speed. I drove once in a convoy, we were asked to set our cruise control at 80. One of them past me, and I was wondering why. I took a look at their screen and they have the same speed, while they have 60+ fps, lower ping, no lag rate. If you still think it's unfair, then you must submit a feedback to one of the administrations with a provided evidence, and how speed hacking looks like. Not just by words.
Congrats to the winners and participants