That really stinks but at least no one was hurt. I know the people who's house and property was damaged probably think that that's the most crap response "at least no one was hurt" but its true. I love the mythbusters so I can't be too mad at them and its not like they were doing anything wrong. They were at a firing range that was suppose to be secure from this type of think happening, one they've used numerous times before without incident.
If my house/property was damaged, I think if they'd pay for the damages, pay to have one of the wall segments with a hole totally removed, give me the cannonball itself and have them turned into a monument of having a mythbuster's cannon ball going through my wall, have all the cast sign it and then let my dad be in meaningful role in an episode then I'd be perfectly happy. My dad absolutely loves the show and my family honestly thinks that kind of job would be a dream for my dad to at least be able to sample.