'how could their accountants and auditors have let things get so bad without pulling the plug' - I've no idea but I doubt if any of them will have been 'signing-on' this morning.
An accountants job is to offer financial advice to the company, prepare their accounts and ensure they are tax compliance. They have absolutely no powers to wind up a company. I presume the accountants told
JS that the company was not viable some time ago but it was up to him what he did with that information.