You need to talk to a solicitor, firstly, to understand all the ins and outs of the situation.
Secondly, it's nonsense to say that your husband wasn't involved or had no dealings with the running of the company - as a director, he's equally responsible.
However, as it's a limited company, he's "liable only to the extent of any unpaid shares held". Unless, of course, he's signed a personal guarantee (which it seems he hasn't).
So stop worrying and call a solicitor.