If Johnny had breached an instruction and had let him through, it might very well have landed him in discliplinary trouble - remember, ours is one of the few jobs where we can be fined out of our wages as punsihment for an infraction. If a copper dispobeys an order and something untoward occurs as a consequence thay can be prosecuted for it. If I'd been ordered to do something, I'd follow it to the letter, notwithstanding any emergency etc that might arise which would permit my to draw upon my professional judgement and disretion to decide on a course of action.
But it wasn't an emergency, Johnny has his orders, and quite rightly he wasn't going to do otherwise. Being a toff and full of ones own self importance is not a lawful justification for an officer in a disciplined organisation to disobey an order.
PS, apologies for terrible typing. not a good day for my meccanno elbow and I've no feeling in one hand.
So what is happening to the undisciplined rabble of officers who let him through the gate on his bike three times earlier in the day and many times previously? If there is such an order they should not be in those positions of responsibility if they cannot follow it and if there wasn't the officer in the story should be disciplined for making up rules for her own benefit (can't be arsed to open the gate) and again not following procedure. Which should it be?