Electrical Conductor Question

I was recently on an inspection when I opened the electrical panel I found that the ground conductor from the pole was cut short and left at the bottom of the panel. The other two conductors were connected to the main breaker, but the grounding conductor was not connected to the grounding nut and the bar to the right in the panel. I have never seen a conductor cable that was not connected to the grounding nut. Am I missing something? Does anyone know why this conductor wire would be cut short and left unconnected in the panel?

The electricity in the house appeared to be fine. Some outlets were not grounded, but most of them were, so there did not appear to be a grounding issue in the house.

I would write this up as

Hazard . ** incorrect grounding needs immediate repair by an Electrician . Please note there could be other major concerns needing immediate repair .