My average time is
250 ms Ö
As far as I know, physiologically your reaction cannot be faster than 140 ms! Considering that it takes around 10-30 ms to press the mouse button, it sums up to 170 ms, which seems legit. So definitely those top guys were cheating somehow, or they accustomed to the average time until green light shows up. And false start is not punished, no penalty for "Too soon" click which makes it even eaiser to cheat (that would be some kind of an anticipation test, not reaction test!)

TIP: try to pressure down the button a little bit before clicking and make the finger more stiff, this will give you some boost in time about 10-30 ms