He probably assumed at most he was at risk for civil penalties -- it's not like he was running drugs or supporting jihad. The company was based in HK, and the obvious legal target; his personal residence in another country should have protected him from civil issues related to the company in HK.

However, once criminal charges and an international task force get involved, doomed. Maybe he could have had better intelligence or lobbyists to figure out criminal charges were brewing, but I don't think his behavior was that unreasonable given the ambiguity of what criminal laws megaupload may or may not have been breaking.