Late appeal - Incapacity Benefit decison

Does anyone have any experience of trying to make a late appeal against an Incapacity Benefit decision?

I just found out that my brother's IB was stopped approximately May 2010 following his medical. He was ill-health retired over 10 years ago and had been on IB since then.

At the time Citizen's Advice Bureau drafted a letter for him, asking for the decision to be reviewed. They said he had a good case but this was unsuccessful.

After receiving the second refusal letter my brother apparently tried contacting CAB and another local agency again for advice but could never get through. I believe he felt intimidated and overwhelmed by the situation (suffers from anxiety and depression amongst other conditions), and did not have anyone to help or advise him which led to him not lodging an appeal or even telling me about it till now.

As he has a small occupational pension I don't think he would qualify for Income-based ESA.

I have noted that a late appeal up to 13 months after decision can be made in 'Special circumstances' - does anyone know what would qualify as Special circumstances, or know of anyone who has made a late appeal?

Thanks