Auto Insurance Claims: Parking lot-both drivers backing up, handicap spot, small claims court

Question

White truck replicates I described an accident earlier but would like more info. My husband was backing out of an unmarked stall. He looked to his left and observed another truck (driver inside) standing with it's bumper approximately 5 feet away, in the drive aisle lane that exits the lot. In fact he was at the exit gate. My husband lifted his foot from the brake after confirming the way was clear to his right. Apparently at the same time, the vehicle to his left began reversing. It travelled 6.5 feet backward while our truck travelled 4 feet backward. Our rear bumper struck a few inches in front of the other drivers rear bumper. We are disputing the 60% liability the ins. adjuster is assigning. In my opinion, the driver of the other vehicle was capable of maintaining a steady gaze in the direction he was going (backward) whereas my husband had to turn his head back and forth. In a couple of seconds that my husband's head was turned the other vehicle moved. Does it matter that he was blocking another parked vehicle and access to a vacant handicap spot to my husband's left when he was stationary? Does it matter that his truck was at the exit and no reasonable person would have expected him to reverse?
Thank you for your valued opinion.

Answer
Generally speaking, blame is assigned to a person who hits another car behind the rear axle, which is why in almost any rear end hit the fault is to the driver in the rear. If you are not satisfied with the insurance company's decision, take the case to small claims court and convince a judge. If you are successful in so doing, then the insurance settlement will go to you 100%.

Your husband should have been watching anything that his truck might have hit and assuming that the other one was about to exit was a mistake.