While one can appreciate Mr. Mahesh Nair's response, his sweeping remark that what the fellow HR Member/Professionals say is 'void' is not condoned. I, as a professional, stoutly protest this, even if it is a mistake. It would have been nice for him to have made his point and also gone through the query. (The candidate in question is a fresher, so experience and a reference from the HR of the earlier company doesn't arise at all.)
While companies claim to have attained CMM Level 5 and use it for publicity, they could have multiple centers/branches and various practices. It could have been on the basis of a center or practice. In this case, the candidate is a fresher, and the company in question is TCS. (Some centers could be assessed at Level 5 on CMM, hence it would be interesting to see if the candidate has a rejection on BGV from the assessed Level 5 on CMM.)
TCS News & Events: Press Release: TCS sets new benchmark in Quality; First software firm to be assessed at Level 5 enterprise-wide in software services and development
Rectification and Redressal
Coming to the aspect of rectification or seeking redressal/addressing the issue, it costs nothing, even if it should mean a rejection. All of us know that there are a lot of professionals who would find it difficult to admit they made a mistake. Who knows, it might cost them their job, so why would they put their neck on the noose? It's easier, therefore, to say, "We found there is nothing incorrect in the BGV, and so we reject."
A trial has to be made irrespective of the result.