The legal actions are a good attemp, try to recover by other methods is nice too, but imho the best solution is to compesate him by voting posts with community's stake. He won in a post over to 1500 hive in HP and HBD so with some post like this one he could easily recover his funds in this chain without the need of other actions.
Solidarity is key in this, if he recover his original funds much better, but I find it very improbable. I will vote this myself for visibility.