[JS] Objects rotate 180 degrees no matter what I tell it

I have a stage that I want to rotate when the player collides with an object. The trigger object has the following script:

 #pragma strict
 private var rotated : boolean;
 private var rotation : float;
 private var result : float = 90;
 private var rotating : boolean;
 function OnCollisionEnter(col : Collision){
     if(!rotated){
         rotation = transform.parent.GetComponentInParent.<Transform>().transform.rotation.z;
         rotated = true;
     }
     if(rotation == transform.parent.GetComponentInParent.<Transform>().transform.rotation.z){
         rotating = true;
     }
 }
 
 function Update(){
     if(rotating && transform.parent.GetComponentInParent.<Transform>().transform.rotation.z < result){
         transform.parent.GetComponentInParent.<Transform>().transform.rotation.z += 1 * Time.deltaTime;
     }
     if(transform.parent.GetComponentInParent.<Transform>().transform.rotation.z >= result){
         transform.parent.GetComponentInParent.<Transform>().transform.rotation.z = result;
     }
 }

It is my understanding that this should rotate the stage by 90 degrees on the Z axis, but instead it rotates the stage by 180 degrees on the Z axis. I have tried changing "result" to other numbers, even negative ones, but the rotation is always 180 degrees on the Z axis.

What am I doing wrong?