He added that the board's internal audit - which looked at a sample of statistics - found no evidence of "deliberate instructions" being given to members of staff regarding the "inappropriate use of waiting times codes".
Mr Weadock replied that his sample was not scientifically determined, and said: "No-one outside Microsoft has ever viewed a Web browser as being part of an operating system".
After comparing the performance of a maquiladora-using firm with that of a control sample, the authors found no evidence of net gain in the use of a maquiladora.