Same as company's relationship with the auditing firm, it might take a scandal to truly overhaul the process.

For better or worse, a fairness opinion is not a guarantee that that a deal is truly fair or good. It is simply a document that reviews a deal's valuation, compares it with the valuations of similar deals and says it's within the parameters. For this reason alone, the banks that issue so-called fairness opinions would be much better served if they called them what they are: valuation reviews.

Boards of directors use fairness opinions as a data point in deciding whether to vote for or against a deal. But perhaps more important, boards use the opinions as evidence that they fulfilled their fiduciary duty in properly reviewing a deal should they be forced to defend themselves against the lawsuit that almost inevitably follows a transaction.

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How can independent opinions be bad? It may seem counterintuitive, but so-called independent banks may be more likely to rubber-stamp a fairness opinion than one of the banks with a long-term relationship with the client because independent banks that do nothing but fairness opinions have so much more to lose by offending the companies that hire them.

Think about it: If an "independent" firm was called in to issue a fairness opinion and refused to do so, who would hire it again? As a result, "independent" banks in practice are often the very definition of "dependent."