I have never seen anyone denied boarding but it is high time someone did something about the management of the crew/staff bus. It is a shambles.
Try getting on the bus at about 1230-1245 terminal bound or 1345-1400 Kitty City bound any weekday and there is a lunch queue a mile long of office staff heading to or from the terminal.
Join the queue, uniform or no uniform...to hell with whether you will be late reporting or not.
I guess it is a case of noodles over schedule integrity.
