Look at theses sentences taken from an esl exercise:
In Nigeria, a three-year-old British girl has been reunited with her parents after being freed by kidnappers in southern Nigeria who had held her for four days.
Margaret Hill's parents, Mike and Oluchi Hill, said she was in good health but "covered in mosquito bites".
I don't understand why it is not "had been holding" as the emphasis is on the duration "for 4 days" not on the result. Am I wrong?