At that point he may be able to sue the state to fix it (or have insurance do it).

And if it’s your fence you can build one of the ones that’s cheap and easy to replace. I wouldn’t be shocked if you could put chain link back up after some straightening. You could use the downed tree to fix the fence if it was split log (not so good at keeping dogs in though)

Just to mention something people might not have ever considered, but basic home owner's insurance does not cover fences as they are not part of the house. I'm sure someone would be more than happy to provide additional coverage for additional fees that would cover a fence, but it's something to keep in mind. I know multiple people that were oblivious to this until their fence was damaged from trees falling on them during a storm.