Task: Question Answering
Input (English): Passage: The film concerns the story of the Boyajian family, who have not celebrated Christmas in 11 years, since their son John was killed shortly before Christmas in 1991 during the Gulf War. With their daughter Jeanie potentially facing a life-threatening illness, George decides they should once again celebrate Christmas; however, Carol adamantly refuses.
George heads to watch over the town's veterans memorial and is accosted by several teenage punks, who are scared off by "Matthew," a hitchhiker passing through town. As Matthew and George talk, Matthew claims to be a Gulf veteran who is the same age as John and served in the same regiment as John, although the two did not apparently know each other.
George invites Matthew to spend Christmas with his family, asking him to tell his wife and daughter that he knew John while they served together. George's ultimate plan is to get the family to once again celebrate Christmas, which works. But as Matthew makes up stories about himself and John, George begins to wonder about Matthew's true identity when his stories include details that only John would have known (including a notable surgical scar from an athletic injury).
At the end, it is revealed that Matthew is actually John  making a supernatural visit (by revealing the scar mentioned earlier) in order to restore the family's Christmas spirit. 
Question: Who apparently did not know each other despite serving in the same regiment?
Output (English): Matthew.