You just said your husband retired. Did he put "retired" anywhere on the unemployment form? I think either way you want to word it -- you do not say he was "forced" to "retire" (and you wouldn't have used the word "retire") -- your husband doesn't qualify for unemployment.
It doesn't matter what the HR person says about accepting severance.
"So do we have a chance if we appeal this disqualification and how should we go about proving his company wrong? "
There is no "we" here but, again, I'm not clear why if you say your husband retired why you believe he's entitled to unemployment benefits. That's a voluntary quit.

