Whilst the airline is grounded, i think you chaps (and ladies) need to realise that there are very few 748 pilots left, and as such should these be sold on, theres only you bunch that can fly them.
As well as that, the only place capable of maintaining them to any decent standard is the Emerald engineering dept.
Whilst i dont know the exact background behind the withdrawal of AoC, i very much doubt it would be because of a trivial reason that could be rectified in a couple of days. I think to be realistic, this will either take the airline off the market for a month or so, or permanently.
You should also probably factor in the commercial damage this will have done - leaving it until the last moment to tell your largest client (RM) that you have no AoC is not the basis for an ongoing relationship. The cleverer thing to have done would be to sub in aircraft there and then, and advise your clients of the situation, whilst assuring them that they will have their contracted uplift etc etc.
Operationally speaking, the airline would still have been grounded, but would have continued to generate revenue, keeping the bank happy. Without the ability to demonstrate the company is a going concern and not a 'car on bricks' the various VC's, banks and financiers cheque books will be firmly shut.
Its easy for me to sit on the sidelines and point out all the deficiencies in MoB and AJ, but that really does not accomplish much, or give the Emerald boys much comfort.
Fingers crossed that they pull through it, but i would not hold my breath this time.