This is one of those plays one would have to see to call IMO. The skill level definately matters Boys/girls/HS/NC2a. If the defender had established legal guarding position and held that position and A1 initiated the contact I would be inclined to call the charge. That is why we get paid the big bucks to make tough descisions like this in a split second and always get them right. Undoubtably in the process leaving both coaches satified!!!