[devdog69]

IMO, you did some things right and some things wrong in this situation:
Right: Just give the ball to A, if he is sure enough to tell you to change your call, change it, it's that simple. Tell him in the locker room that there is a proper way to 'offer help' on an out of bounds call and explain to him to come to you and offer information and then let you decide. In this situation, I tell my partners before every game 'if you are 110% sure on an OB call that I missed it, come to me, give me information, and I will change it 100% of the time'.
Of course, you already know the part about not pregaming, but I would have definitely told him not to 'overrule' your call in that manner.