There is an issue at B3 and F holding points that can topple the nav systems of what seems to be only Dash 8s and SAABS. It doesn't happen all the time. Something to do with either the train or fuel line depending on who you ask.
That (might) have been the reason they were so far back if it was one of these.
While we are at it: If you know you will not be ready by the time you get to the holding point, then too bad. Taxi there and finish getting ready, don't taxi down B4 at 2km/h and delay everyone else on B and C just in case you may be able to roll on and go.
