Car Accident

This is in Wisconsin

My dad and his neighbor across the street were both backing out and hit each other. My dad has known the guy for over 30 years. His wife passed recently. He opted to be nice and gave him $1k to cover some of the repairs with the understanding that they would leave insurance out of it. Neighbor accepted it. Got his bumper repaired. Said something was wrong with his brakes and asked for more money. My dad said no. He went and got insurance involved. My dad never actually gave him the insurance info, but he did mention he had acuity, so I guess that was enough for the neighbor…

Point of origin in the road is apparently unknown. Neighbor argues that since he was already turning and my dad was backing straight up, that it’s clearly my dad’s fault. Having common sense, I pointed out that there were cars parked on our side of the street so my dad had to back out further before he could start turning, so the neighbors argument is irrelevant.

My dad is a people pleaser and is backing down from the fight. He originally asked his contact at American advantage and was told it wouldn’t go anywhere and not to worry about it. Acuity is the actual insurance provider and they called my dad just grilling him on it though. He’s pretty sure his rates are going to go up.

My question is, if the insurance company pays the neighbor, can we take him to small claims court to get the $1k back? Or what other options do we have? My main goal is just to fuck with him because he’s an asshole. In my mind, after he took the money and agreed it was settled, he shouldn’t have gone to insurance.

TL;DR

Dad and neighbor hit each other backing out of their respective driveways in Wisconsin. Dad gave neighbor $1k to help with repairs and leave insurance out of it because he felt bad for the guy having lost his wife recently. No clear fault on either side. Neighbor took money and made repairs and went to insurance anyways. What can we do?