If your friend (or friend's business/organization) is listed as the registrant on the domain registration, most registrars have a manual process for allowing the registrant to (re)gain control over their domain name. This typically involves some form of photo identification, formal request on company letterhead, or some other means of your friend proving he truly is the owner of the domain.
However, if ServWeb registered the domain in their own name, your friend may have little recourse, because as far as eNom is concerned, ServWeb would be the registrant. If ServWeb just closed up shop, I suppose there's an outside chance your friend may be able to contact someone who used to work there that could still login to eNom to help him out. On the other hand, if ServWeb filed for bankruptcy and creditors are dividing up the remaining assets, the domain names registered in their name could be considered assets to be sold or auctioned to cover any of ServWeb's remaining liabilities.
Has your friend actually tried to contact or visit ServWeb to verify that they really are out of business?