Simple LOD not working correctly.

I have created a simple LOD method here:

 public static void SphereLOD(Vector3 camPos, Mesh mesh)
     {
         newVectices = new Dictionary<uint,int>();
         List<Vector3> meshverts = new List<Vector3>(mesh.vertices);
         normals = new List<Vector3>(mesh.normals);
         uvs = new List<Vector2>(mesh.uv);
         indices = new List<int>();
         Vector3[] closest = new Vector3[9];
         closest = mesh.vertices.OrderBy(v=>(v - camPos).sqrMagnitude).Take(9).ToArray();
         Vector3 originate = (closest[0] + closest[1] + closest[2] + closest[3] + closest[4] + closest[5]
              + closest[6] + closest[7] + closest[8]) / 9;
         float length = ((closest[0] - originate).magnitude + (closest[1] - originate).magnitude +
              (closest[2] - originate).magnitude + (closest[3] - originate).magnitude +
              (closest[4] - originate).magnitude + (closest[5] - originate).magnitude +
              (closest[6] - originate).magnitude + (closest[7] - originate).magnitude +
              (closest[8] - originate).magnitude) / 9;
         closestlist = new List<Vector3>(closest);
         vertices = new List<Vector3>(closest);
     
         oldclose = closestlist;
         int[] triangles = mesh.triangles;
         if ((closest[1] - camPos).magnitude > (2 * length))
         {
             
             for (int i = 0; i < triangles.Length; i += 3)
                 {
                 int i1 = triangles[i + 0];
                 int i2 = triangles[i + 1];
                 int i3 = triangles[i + 2];
  
                 int a = GetNewVertex(i1, i2);
                 int b = GetNewVertex(i2, i3);
                 int c = GetNewVertex(i3, i1);
                 indices.Add(i1);   indices.Add(a);   indices.Add(c);
                 indices.Add(i2);   indices.Add(b);   indices.Add(a);
                 indices.Add(i3);   indices.Add(c);   indices.Add(b);
                 indices.Add(a );   indices.Add(b);   indices.Add(c); // center triangle
                 }
         }
         for(int i = 1; i < vertices.Count; i++)
         {
             meshverts.Add (vertices[i]);
         }
         
         mesh.vertices = meshverts.ToArray();
         //mesh.normals = normals.ToArray();
         //mesh.uv = uvs.ToArray();
         mesh.triangles = indices.ToArray();
         
         newVectices = null;
         vertices = null;
         normals = null;
         indices = null;
         
         
     }

From here, I go into the a script and call MeshHelper.SphereLOD(camPos, mesh); and it should subdivide the closes 9 vertices to the camera when the camera gets close enough. The problem is that when I apply this to any object, strange things happen. The object's triangles are thrown about and the mesh is destroyed. Can anyone help me isolate the problem?

Edit: Here is the GetNewVertices code:

 static int GetNewVertex(int i1, int i2)
     {
 
         uint t1 = ((uint)i1 << 16) | (uint)i2;
         uint t2 = ((uint)i2 << 16) | (uint)i1;
         if (newVectices.ContainsKey(t2))
             return newVectices[t2];
         if (newVectices.ContainsKey(t1))
             return newVectices[t1];
 
         int newIndex = vertices.Count;
         newVectices.Add(t1,newIndex);
  
  
         vertices.Add((vertices[i1] + vertices[i2]) * 0.5f);
         normals.Add((normals[i1] + normals[i2]).normalized);
         uvs.Add((uvs[i1] + uvs[i2]) * 0.5f);
  
         return newIndex;
     }

These images show that the object is responding to the camera position (see triangles pulling toward it) but not in the intended manner.

Image 1

Image 2