Sorry to hear about your husband's difficulties.
The first thing to ask is whether your husband's scheme is based upon defined contributions or whether it is based upon defined benefits.
Let me explain the difference - a defined contributions scheme is sometimes referred to as Money Purchase. The pension benefits depend upon the the growth in the investments in the Pension Funds, manged by the trustees. Each year during the savings, one typically gets a statement and at the end when one retires, the some of money is used to buy a pension. It is NOT linked to the salary on retirement.
Defined benefits schemes are becoming as rare as hen's teeth (unless one works for the Government) because the risk of any funding shortfall is with the employer. The pension is based on a formula which includes the no. of years worked and the fianl salary. They are sometimes called final salary schemes.
I suspect your husband does not have one of these.
Now, as to whether anyone can be held accountable for the mess-up.
Pension projections are often assured for a short period of time when they are made. Was there anything on the projection to say how long the 'quote' would last?
I suspect what has happened is that he has a defined contributions scheme and the 'quote' was based upon investment values that fell sharply in September - global recession and all that stuff. However the projection should have made this clear or a period of holding firm should have been quoted.
Please tell us what type of scheme he has.
Your route to complaint (if you have one - not sure that you do yet - we need answers to my answers) is likely to be via this crowd.
http://www.thepensionsregulator.gov.uk/members /index.aspx
There is some useful stuff in this website - could I recommend that you