Well when you make a plan - you assume the "actors" play their role - but in this case all actors are not Q-clearance and they are bad news and unreliable - so sometimes the plan will go a little off schedule, but that is probably incalculated too. I assure you - this team (Q) do not only have a one-way-plan - they have multiple schedules to go into action in case  the "right path" is interrupted!