my opinion: he is member of a very good team. they're at war with the Hell, so why not "push" (but legal !!) one team member with nice but still legal "exchange courses" for dollar until he has so much points that he destroy 2-3 players from HELL ?
nice exchange courses in the team plus farming with that much carriers ( so you dont need to farm that much dollar, because you get it from your team) --> not surprising he is TOP1 now
nice exchange courses in the team plus farming with that much carriers ( so you dont need to farm that much dollar, because you get it from your team) --> not surprising he is TOP1 now