Well, you may get different opinions from different folks. I would say you are ok for accepting employee self-certification that the employee lacks other resources to satisfy the need. As to approving the AMOUNT/NATURE of the need, yes, it is possible to accept employee certification, but the procedural requirements are fairly rigid. Many employers/TPA's find it easier and "safer" to continue to request source documents for substantiation of the nature and amount of the hardship need. The IRS audit guidelines give guidelines for acceptable substantiation for either source documents, or a "summary" of information, etc.
FWIW, we still have our clients obtain source documents. (bills, eviction/foreclosure notices, etc., etc.)