Random Inspection/Reefer

Has anyone else ever had this happen before? I was driving along happy as could be when I here a short burst of siren.
It was a Indiana State Trooper with another lady. I asked what did I do. She (trooper) says oh nothing just a random check on reefer drivers. The trooper did all the regular checks, paperwork, invoices,med card etc...
Then the other lady in the squad tells me she is with the sanitation department. They need to check loading of trailer, what I was hauling, temp of the trailer. Then she asked me if I had certification in food service handling. I happened to have it because I kept mine from my food service days, but never had that question asked before. She also asked if we had a H.A.C.C.P. guideline for food hauled i.e. record of tracing the food from when it was loaded, possible contamination sites, etc.. just curious since this type of inspection with the health department has happened to me before.