Leaderboards can be reset, but it is not easy to do so. Another game, Toy Soldiers: Cold War, had a far worse bug. Someone got the number one position on the all the leaderboards, even though the score is an odd number, yet it is exactly the same on all boards. It is also impossible to get that score on most of them, since many are timed and have a finite amount of targets to get points on. It's likely he hacked the game illegally. The company is aware of this, but they have to work with MS to fix the problem, and could not give a definite answer as to when that would be.@Mike
is it possible to reset the leaderboards for a table easily? Bugs like the MB jackpot make me think about that.