I'm not sure about the re-opening of the unemployment claim but your husband may have a claim for overtime pay, meal and rest breaks if he was misclassified as a salaried employee. Talk to a lawyer. The call should be free.
Technically, he would not be going back to the old claim, but instead filing a new claim based on the loss of the most recent job. He will have to prove that it was not a voluntary quit, as the EDD will define that term.
Take a look at the following links to the EDD website that thoroughly discusses that concept.
Good luck to you.
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