I have no sympathy for the old guy. He clearly is no longer capable of driving and the longer he deludes himself that he can, the more people are going to be at risk, regardless of how slowly, or how careful he thinks he's being.
An almost identical thing happened almost a year ago to me, however I was on a motorbike at the time. I could see how blind, frail, slow, shocked the 80 year old driver was, but with a broken ankle, I certainly made my feelings clear to the doddery old bat.
I'm pretty certain the police took her driving license away, and I would have pushed they do the same to this OAP.