He probably didn't cheat. I found a glitch in Avoider. On the high scores list I once got over 9000 points but I barely did anything. Sometimes when one of the blocks hits a corner of the play area, i.e. it bounces off the top and right side at exactly the same time, it gets stuck to the top edge and it just keeps moving left to right but still stuck to the top.
In my game it happened with all three blocks and so I just put the cursor towards the bottom of the play area and went to make myself a drink. By the time I was back I had racked up almost 9,000 points. Then one of the blocks became unstuck when I was too far from the computer to do anything about it and I lost the game.
He probably had the same thing happen.
