Actually, he did NOT become a citizen unless she had been there for at least one trip prior..
The child would not have been issued a Russian passport and a US visa unless the adoption had been finalized in a Russian court.
The only difference in the Child Citizenship Act is the type of visa a child comes comes into the US on. The IR-3 is issued when both parents (or in the case of a single parent, just the one parent) have seen the child prior to finalization in the foreign country. IR-4 visas are when only one parent has seen the child and must “readopt” in the US because the non-travelling parent has to see the child and give consent. Children travelling on IR-3 visas obtain citizenship automatically upon entering the US.