My Coworker Almost Hit Me With Their Car And Now Wants Damages.

So a group of coworkers and I had just gotten off the clock when one of our other coworkers showed up. After we talked for a moment, I was behind the car and they slammed the car in reverse and the three of us that weren't the driver have all said it looked like they were going to hit me with the car, likely accidentally, but still going to hit me. Now, in the time that I saw the reverse light come on and saw the car move a bit, I had no time to get out of the way without diving onto asphalt, so I instead sat on the back of the car. Now this coworker is saying that there is a small dent that he wants me to pay to replace the entire trunk for. Legally, who would be at fault and why? Edit: I said this in a comment but it is one of the main reasons I am hoping not to involve law enforcement or lawyers. The driver has 4 family members in the workplace, and one of them is a direct manager for both of us. Additionally, I've already told the driver it would be illegal for him to use that against me, but obviously things don't always happen in a way i could prove.