Kevin Lawley was felled by the Ford Transit shortly after arriving on the car park of the Brunswick Inn on Crankhall Lane, Wednesbury, Wolverhampton Crown Court was told.
He had stopped on the opposite side of the road to drop off a friend when people ran over from the pub to reveal the trousers of his four year old grandson had just been pulled down by a customer called Nazeir Ahmed who had driven off.
Mr Lawley told the jury: "I heard different stories and was then told he had pulled back onto the car park. I went over wanting to find out what had really happened, not hit him. He was in his van arguing with another man standing outside."
He accepted the man might have told the defendant to get off the car park but denied the driver asked him to move after he stood alongside the vehicle and cried "oi"to catch his attention.
Mr Lawley continued: "The van went into reverse. The wing mirror hit me on the shoulder knocking me backwards onto my side. The front wheel went over my left ankle, up the leg and straight off my hip. Then it moved forward and the tyre went back over me before it drove away."
He suffered three fractures of the leg together with a deep laceration on his ankle which needed surgery and kept him in hospital for several days following the incident on May 11 2018, revealed Mr Dean Easthope, prosecuting.
Ahmed did not report it but, when contacted by police, gave a voluntary interview two days later in which he admitted that no other customer at the pub found his "joke" funny. The 39-year-old father of four, who had been drinking brandy, told the court: "It was my stupidity. People started shouting and I walked out."
While sitting in his vehicle waiting for a taxi home the van was repeatedly rammed by a Kombi van before and he drove off only to return soon afterwards to hunt for a missing key.
He maintained: "I was approached by a chap who shouted at me to get off the car park. I did not know Mr Lawley at the time but he came up and stood next to him. I asked him to step away as I tried to reverse.The other man said he had fallen and started to punch me when I tried to look." He drove away from the scene.
Ahmed, from Nicholls Street, West Bromwich, denied causing serious injury by dangerous driving. The jury has retired to consider its verdict.