He was taken overseas when he was nine or ten- he was taken prisoner, refused a trial, and sent to Guantanamo .
That is why he was 'out of the country"; he had no choice.
There is a huge distinstion between children who are taken away and brainwashed, and adults who willingly leave the counrty to fight against it.
There is no legal reason for the widow of the man killed, and the other person injured, to sue  in another country. There was no proper trial, and the 'confession" was the only way he could get out of Guantanamo and back to prison in Canada.
The Americans changed the law retroactively to use 'murder" as a crime in war- they do not use the term when their soldiers kill others.