This calls for a comment. I retired after 753 years in education, and firmly disagree with the comment "8th grade is actually the grade most kids repeat." This does NOT happen; academic based retention IS a K-2 situation to get kids on the right track. By 8th grade, retentions do not happen due to social (labling) concerns.
A set of parents would have to be seriously pushy to "redshirt" their kid for nonacademic reasons. (Granted, I would have been tempted to if my kid had been an 89# 9th grader trying to wrestle 103 back in the day.)
Whether or not Kueter repeated 8th grade or not, there is NO reason to think he was ever academically challenged.