Negative transitions were controlled in much the same way as positive transitions. Instead of the thrower driving against the defender it was the defender that took the initiative and closed the attacking space before the attacker could take control. In other words the defender was making an effort to counter attack. Neither maneuver appeared to offer a difference in control over the situation. Neutral transitions are, from one perspective, the opposite of a positive of negative transition.
Neutral transitions occur when the defender forces the attacking space open.
You must realize what is being said here. The attacker gets his throw started, and starts closing the attacking space. The defender, recognizing his perilous position, then forces the space open. The space is forced open at the hips or shoulders. Interestingly, forcing the space open at the shoulders appears to occur because the defender recognized the pending attack early and was able to take evasive action.