Limited liability and directors

Client is limited company, director and shareholders are husband and wife.  Company dependent on husband working/generating income.

Client is considering a new 5 year lease for a business vehicle (akin to a refuse truck), as I understand it is an operating lease but have not seen the contract.

The terms is for 5 years, if the client does not fulfil the 5 year lease the company is responsible for the remaining lease payments from that point (although Lease company have indicated if they can re-lease the vehicle, the liability is lifted).

Client is concerned that if he is hit by the proverbial bus or incapacitated, his limited company would fold but what would happen with this potential liability.  

My first thoughts that being a limited company 'protects' the wife and/or husband from personal liability, and said debt would go down with the business, am I right in thinking that there would only be recourse to the directors if they had acted unlawfully or entered into arrangements that are not in best interest of the company - this is not the case, company is profit making just dependent on the husband.

They don't have keyman insurance in place but do have personal insurance policies that cover a personal bank loan they took out to cover bank finance to set company up.  Is this their risk point (ie no keyman insurance in place)?. Or would they need to ensure that any insurance policy covers this lease commitment also, how far does one take it??

Just wanted to throw it out there to see what experience others have of this