Oh yes, certainly that could never backfire.
Its not weird at all. They would prefer not to know about the trampoline. This way they can collect the policy premium and still disclaim after someone is injured. Win win. The reason he does this is because he knows he is getting under your skin. If you just left it alone it would stop. In fact, you should offer free soda to the kids who come play on his trampoline.
Have you ever considered becoming a beekeeper?