Arne, you didn't do a mistake, besides restarting the server, but by rules the T has to open the cells in order to be a freeday. Now the rules talk about opening from button. Snow is the only map where the cellkeys open all the cells. In every other map the cellkey only opens one cell and if the rebel want's it to be a freeday, he must go and open the other cells from button.
The JB admins have silently agreed that if you open the cells with cellkey in jb_snow, a T must also open the button before the CT in order to have a freeday. Now most of the cases the Ts open their cells fairly quick and thus the CTs just give up and let them have a FD. However, if all the CTs are in position and the cells are opened, they're free to keep commanding and kill everyone who's disobeying the commands, of course after giving warning shots.
I hope that this thing is now cleared out and someone above should also modify the jb rules, with adding a statement that "If a T opens cells using cellkey, it's not a freeday until he opens the cells from button as well."
Sincerely,
The JF