He was allowed in this time - but not allowed out. It seems that during his holiday the law was changed. As in the old days, Russian nationals living abroad again need a visa to visit their own country and an exit visa to leave. There was no announcement of this.
He is now stranded in Russia, having to go through the lengthy and tortuous process of obtaining an exit visa. And then money, representing a couple of years' wages to his aunts, will have to be found for a new ticket. Both his parents are here and he goes to school here. Is there any logic in keeping him there?
In my long experience of Russia, starting as a Morning Star Moscow correspondent, I always argued that the arbitrary, vicious, illogical, unpredictable nature of its bureaucracy went deeper than any political system. I feel I have been proved right. But in the old days even the most malicious bureaucrats showed mercy to children.