In addition, the "immediate effect" part implies to me that he has been fired. If an executive is leaving on good terms, he sticks around to help with the search for his replacement and to smooth the transition. He doesn't just suddenly go. Especially in a public company where investors value stabilty.
Unless it truly was for personal reasons - if something bad happened with or in his family, you might not want to stick around, search for a replacement, smooth things out - you'd probably want to get there (especially as they're in another country) and be there with them as soon as possible. Just my view though, but surely it doesn't necessarily mean fired?