Better yet block it in next time. Make it to where he has to come talk to you before he can drive it. If he does something stupid like free it himself get the police involved for trespassing or damage to property if anyIf I were to ever want to flatten someone's tire, I'd probably just use my heel to break the stem. I've got a house that was willed to me.. that I have a problem with neighbors wanting to park their vehicles under the car port.. despite the fact that I have no parking signs. When I've called a wrecker to have them towed, the owner runs out and moves the car. I've thought about stomping the valve stems so the wrecker has time to get the car.