Annotations and Screenshots not lining up

I'm using Unity to take annotated screenshots of images for a machine learning project. For whatever reason, sometimes the label of the image and annotation number don't line up. Sometimes it'll be off by one, as in, image 7 will correspond to annotations 6. Does anyone see why that might occur in my code?

```

public class randomizer : MonoBehaviour {

 public int model_num;
 public float timer;
 public float rand_anim_sleep_time;
 float[] camera_coords = new float[3];
 public string model_name;
 public bool model_up;
 public GameObject selected_model;
 public GameObject camera;
 public GameObject ball;
 public Rect bound_box;
 
 public int counter;
 
 // Start is called before the first frame update
 void Start()
 {
     camera = GameObject.Find("Main Camera");
     ball = GameObject.Find("st_ball_000");
     counter = 0;

    
 }

 public static Rect GUIRectWithObject(GameObject go)
 {
     Vector3 cen = go.GetComponent<Collider>().bounds.center;
     Vector3 ext = go.GetComponent<Collider>().bounds.extents;
     Vector2[] extentPoints = new Vector2[8]
     {
         HandleUtility.WorldToGUIPoint(new Vector3(cen.x-ext.x, cen.y-ext.y, cen.z-ext.z)),
         HandleUtility.WorldToGUIPoint(new Vector3(cen.x+ext.x, cen.y-ext.y, cen.z-ext.z)),
         HandleUtility.WorldToGUIPoint(new Vector3(cen.x-ext.x, cen.y-ext.y, cen.z+ext.z)),
         HandleUtility.WorldToGUIPoint(new Vector3(cen.x+ext.x, cen.y-ext.y, cen.z+ext.z)),
         HandleUtility.WorldToGUIPoint(new Vector3(cen.x-ext.x, cen.y+ext.y, cen.z-ext.z)),
         HandleUtility.WorldToGUIPoint(new Vector3(cen.x+ext.x, cen.y+ext.y, cen.z-ext.z)),
         HandleUtility.WorldToGUIPoint(new Vector3(cen.x-ext.x, cen.y+ext.y, cen.z+ext.z)),
         HandleUtility.WorldToGUIPoint(new Vector3(cen.x+ext.x, cen.y+ext.y, cen.z+ext.z))
     };
     Vector2 min = extentPoints[0];
     Vector2 max = extentPoints[0];
     foreach(Vector2 v in extentPoints)
     {
         min = Vector2.Min(min, v);
         max = Vector2.Max(max, v);
     }
     return new Rect(min.x, min.y, max.x-min.x, max.y-min.y);
 }

 // Update is called once per frame
 void Update()
 {
     // initializes new UnityEngine.Random model
     if (timer == 0)
     {
         rand_anim_sleep_time = UnityEngine.Random.value;

         model_num = UnityEngine.Random.Range(0, 10);
         model_name = "model_00" + model_num.ToString();
         selected_model = GameObject.Find(model_name);
         Vector3 selected_model_position = new Vector3((UnityEngine.Random.value*6) - 3, 0, (UnityEngine.Random.value*6) - 3);
         selected_model.transform.position = selected_model_position;
         selected_model.transform.rotation = Quaternion.Euler(0, (UnityEngine.Random.value*360) - 180, 0);
         
         Vector3 ball_transform_position = new Vector3( selected_model_position[0] + (UnityEngine.Random.value*2) - 1, .1f,  selected_model_position[2] + (UnityEngine.Random.value*2) - 1);
         ball.transform.position = ball_transform_position;
         

         camera_coords[0] = (UnityEngine.Random.value*10) - 5; // [-5, 5]
         camera_coords[1] = (UnityEngine.Random.value*2) + 1; // [1, 3]
         camera_coords[2] = (UnityEngine.Random.value*-9) - 1; // [-1, -10]
         camera.transform.position = new Vector3(camera_coords[0], camera_coords[1], camera_coords[2]);
         camera.transform.LookAt(ball.transform);
         camera.transform.rotation = Quaternion.Euler(UnityEngine.Random.value*40 - 20, UnityEngine.Random.value*40 - 20, UnityEngine.Random.value*40 - 20)
         
         bound_box = GUIRectWithObject(ball);

         selected_model.GetComponent<Animator>().Play("", -1, 0);      
     }

     timer += Time.deltaTime;
     // lets the animation play out before killing
     if (timer > rand_anim_sleep_time && timer < rand_anim_sleep_time + Time.deltaTime)
     {
         string folderPath = Directory.GetCurrentDirectory() + "/imgs/";
         var sr = File.AppendText(folderPath+"annotations.txt");
         ScreenCapture.CaptureScreenshot(System.IO.Path.Combine(folderPath, counter.ToString() + @".png"));
         sr.WriteLine(counter.ToString()+ ","+bound_box.ToString());
         sr.Close();
         
         
     }
     
     if (timer > rand_anim_sleep_time + .1)
     {
         counter++;
         Debug.Log(counter);
         selected_model.transform.position = new Vector3(-10, -10, -10);
         timer = 0;
     }

 }

} ```