Mesh triangles don't match wireframe view?

So I have a mesh of a sphere made out of lots of fairly evenly shaped triangles. When I switch the scene view to "wireframe", I can easily see the triangles of my mesh.

I assumed that if I got the mesh.triangles, it would provide me with... those triangles I can see in wireframe view.

But that doesn't seem to be the case. As I loop through the triangles... the majority of the time, yes, it's giving me the three corners of a triangle, which I can find using my eyes looking at the wireframe mesh, if I find them on the mesh.

But once in a while mesh.triangles is giving me three vector3 positions that do NOT make up any sort of triangle at all, at least none that I can see looking at the wireframe. It's usually three vertices that are fairly close together, but sometimes they form more like a line, not a triangle. Other times, one of the three points will jump a whole triangle away, and there is no way that vertex is part of any triangle, there is no "edge" that connects that vertex to the others, it's not a valid triangle on the mesh, at least not according to what I see looking at the wireframe.

Can anyone explain why mesh.triangles is giving me this?

Here's my code:

     Mesh mesh = transform.GetComponent<MeshCollider>().sharedMesh;
     int[] tri = new int[mesh.triangles.Length];
     Vector3[] ver = new Vector3[mesh.vertices.Length];

     mesh.vertices.CopyTo (ver, 0);
     mesh.triangles.CopyTo (tri, 0);
                 
     int vertlen = ver.Length;
     int trilen = tri.Length;

     int[] UnfinishedVerts_Index = new int[vertlen];
     for (int a = 0; a <= vertlen - 1; a++) {
         UnfinishedVerts_Index[a] = a;
     }

     for (int triangle_loop = 0; triangle_loop <= UnfinishedTriangles_Index.Length - 1; triangle_loop += 3) {
 
         int TriVert_Index1 = tri[UnfinishedTriangles_Index[triangle_loop + 0]];
         int TriVert_Index2 = tri[UnfinishedTriangles_Index[triangle_loop + 1]];
         int TriVert_Index3 = tri[UnfinishedTriangles_Index[triangle_loop + 2]];

         Vector3 Trivertex1 = ver[TriVert_Index1];
         Vector3 Trivertex2 = ver[TriVert_Index2];
         Vector3 Trivertex3 = ver[TriVert_Index3];
 
     }

In the above code, Trivertex1, Trivertex2 and Trivertex3 should be the three vertices of the triangle. And they usually are. But once in a while one of them jumps a whole triangle away, or something like that.

I thought it was my mesh, like maybe my mesh was "bugged". But, I can clearly see the triangles on my mesh when I look at it with wireframe view. If it was my mesh, I should see an "edge" connect to these out-of-place vertices, right? I see only perfect triangles in wireframe view. And mesh.triangles isn't giving me the same perfect triangles I see.