That will be the only criteria from admissions. Carr's parents "held him back" so he could take a mission trip or something (I don't remember the whole story) and he took classes during that time. He's the same age as the '23 kids and he's taken extra course work. Go look at the admission criteria. There isn't anything that should be a deal breaker.
And why do you think his parents wouldn't "let him"? That doesn't make sense to me.