hmmm... just for the avoidance of doubt:
countdown delays the reaction of a trigger for a certain length of time, determined by the min, max and mid values. thus if the triggering unit walks into the area then leaves, the trigger will fire after the countdown is complete, regardless of whether the triggering unit is present or not.
timeout requires that the condition of the trigger must be met for a certain length of time, determined by the min, max and mid values. thus if the triggering unit walks into the area then leaves before the timeout is complete, the trigger will not fire.