I was worried !!

I was out today. I always have our emergency phone ,(for the wildlife hospital), on me. I pulled over to answer it, I don’t any fancy hands free thingey. As I was talking I noticed this workman lying on the ground, on the other side of the road. No other vehicles nearby. He was very still. I continued and finished my conversation. I grabbed a photo, then he moved and sat up. I called out that he had me worried. He laughed and said there was a valve he was checking !!!! , and thanked me for worrying!!!!!Only when he got up and walked away did I see a small cover. It must have been very deep as his whole arm was in hole!!!