- The 82 were released on Saturday following months of talks and the exchange of a number of suspected militants held in government custody.
- Elizabeth Pearson, a Boko Haram specialist who studies women and conflict, said the case of the Chibok girl who refused to leave was "likely to be quite prevalent".
- Human Rights Watch has accused the government of failing to respect the girls' privacy by publishing their names and for parading them at a photo-call.
A schoolgirl who was among more than 200 kidnapped by Boko Haram in 2014 refused to be part of a release deal because she is now married to a militant fighter, Nigeria's government said Tuesday.
The disclosure underlines the complex psychological effects of a lengthy captivity, and gives an indication of the work required to rehabilitate and reintegrate those released.
Boko Haram has used kidnapping as a weapon of war, seizing thousands of women and young girls as part of its eight-year quest to create a hardline Islamic state in northeast Nigeria.
Men and boys have also been forcibly recruited to fight in its insurgency, which since 2009 has killed at least 20,000 in Nigeria alone.
Presidency spokesman Garba Shehu said the jihadists had initially agreed to release 83 of the teenagers who were abducted from their school in the town of Chibok in April 2014.
But he told the local Channels television station: "One said, 'No, I have a husband. I'm happy where I am'. And then 82 came back."
The 82 were released on Saturday following months of talks and the exchange of a number of suspected militants held in government custody.
Twenty-one of their classmates were freed in October last year; three had previously been found or escaped. Talks are understood to have started to free all or some of the remaining 113.
Testimony from former hostages in the brutal conflict has revealed that Boko Haram forced many women and young girls into marriage, and that rape and sexual violence were commonplace.
Some were forced to work as domestic slaves for extremist fighters and even deployed to the front line carrying ammunition during attacks.
Elizabeth Pearson, a Boko Haram specialist who studies women and conflict, said the case of the Chibok girl who refused to leave was "likely to be quite prevalent".
"From what we know of other young women who've returned, the relationships with their captors is very complex and at times quite ambiguous," she told AFP in an email exchange.
"We assume because they are abducted they are therefore likely to resist their captors. In fact they have to develop relationships of some sort in order to survive."