The company  issuing the report in error, initially, I would believe, should be responsible.

  The examiner's liability might be affected by his/her status:  is the examiner an outside provider or an employee?  If outside, what is the nature of his arrangement:  independent contractor, subcontracting firm, or otherwise?  Professional Liability Insurance at play?  Was there transcription or communication error and if so, on whose part?  What internal standards & practices are in place to check and verify a report?  Was there any sort of other reasonable disclosure to the end client which would be obvious to a common person reading the provided materials?

  I would want to investigate these questions and all matters related to the situation before ascribing blame for the error.  Most business problems boil down to communication, but sometimes it's simply a matter of a single human error too.  Research the research methodology and ensure that industry standards have been followed.  Review the business history of the provider as well.