My father told me about some stories in Egypt that is quite sad. It's partially a family/Church problem more than it is a personal problem. Still, there is personal responsibility, but the environment is a big influence on the decisions of a person. Many Copts would grow up born and baptized in the Coptic Church, but their family not much religious, and they get more support and help from Muslim neighbors than they do from their own Church. Some churches and priests don't harbor a nurturing and loving attitude toward the congregants, but more or less a negligent manner (even for some priests' own families, which is quite sad). Thus, you will always have that Muslim "evangelist" that will lead you to a place of comfort in their own religion, and in that manner you lose you own people.
So, was this Russian man really lived a life of Orthodoxy in the first place? I think this quote answers the question:
who was born an Orthodox Christian but had close links to Islamist rebels in Chechnya
I wouldn't be surprised if Chechniyans took care of him very well to attract him to Islam.