Onside Kick Clarification

[Lions Fan]

I attended an Ohio high school football game last night where an onside kick was attempted. The kicker kicked it in the air towards the right sideline and one of the kicking team players ran down and caught it in the air. The ball traveled 20 yards in the air and never touched the ground. A penalty was called on the kicking team because the referee ruled that the ball must first touch the ground before the kicking team can take possession. Does anyone know if this correct and possibly the rule number in the rule book?? Thank you.