Metal post fallen over leaving hole in ground edge of road pavement

The hole on the edge of pavement road was hidden by leaves. No signs to say it’s there. Elderly gentleman walking towards us stepped aside to pass us when his foot went down the hole. He fell forward narrowly missing the next metal post, but hit his mouth on the body of parked car next to it. He then fell to the ground. Fortunately he appeared to be ok apart from his bleeding mouth. He did not want to make a fuss but agreed I could report the incident. I then spoke to the bar staff in the Woodstock Arms Pub who said they could do nothing about it as they had reported it to the council 3 times already. I then took a road bollard from by the parking machine and placed it over the hole. I feel this is a real danger to other pedestrians and people parking their car.