[Javascript][Coders strike back] Standard output bug : player2's output move player1's pod

It had taken me a while to really see what was going on, but I finally found the bug.

My code ends like this :
st = nextCheckpointX + ’ ’ + nextCheckpointY + ’ ’ + t;

Each time my pod crosses the checkpoint, I get some missy outputs like this one :
Error output : 10725 4997 0
Standard output : 12008 1994 100
Impossible !!

I finally found out that at these moments, the standard output for my pod is exactly the same than the boss’ standard output.
(I made a printscreen, but I am still not allowed to post it here.)

It looks like there is a bug when the code is tested that mixes the standards outputs of the two players… I get the same thing when I submit my code.