I'd have to agree that they had plenty of justification to charge him. Same goes with those moronic skiers who don't obey warnings about some slopes being off limits. If the authorities are saying "Don't ski/fish/drive/stay in this area due to dangerous conditions", be it an evacuation order due to a hurricane, or anything like that, people should realize that if they need to be rescued due to their stubbornness or stupidity, they will be charged for it.
I'm thinking about highways today, because our highways in Northeastern Ontario were closed this morning due to treacherous conditions. Often the police simply warn motorists to stay off the highways but leave the highways open. Now if someone, for whatever reason, travels such a highway after the warning, are they liable to be charged all the itemized costs involved in an accident?
However, in this situation, if the authorities are leaving highways open, and don't close down and clearly indicate the risk and danger, then they should not be charged.
However, if authorities leave highways open, I do think they shouldn't be charged.