Thank you very much for all the responses. My reason for not pursing it while was still employed is that the employer was paying 100% of my health insurance and therefore I I thought I could just handle it without making a claim, and utilize my health insurance, not knowing that a termination was pending. Lesson learned...

I appreciate the case law reference as well. I took the same route to and from the parking lot that my manager took every day.
The parking garage was not mentioned in the rules & regulations as being off limits, but I believe there might be a sign at the entrance where cars enter that says "no pedestrians" or something of that nature. Does that complicate things even further?