Even if the U.S. government wanted to manipulate monthly jobs figures, it would be impossible to accomplish, said a former head of the U.S. government’s labor statistics agency.

Accusations that the government had manipulated the latest employment report spread across Twitter and other forums Friday after the U.S. unemployment rate fell to its lowest level since President Barack Obama’s inauguration. Among those questioning the better-than-expected report was former General Electric Chief Executive Jack Welch, who tweeted the suggestion that the “unbelievable jobs numbers” were fabricated to help Obama’s electoral chances in next month’s presidential election.

But, Keith Hall, who served as Commissioner of the Bureau of Labor Statistics from 2008 until 2012, said in an interview Friday that there is no way someone at the agency could change any of the data from its two monthly employment surveys. The significant improvement in the unemployment rate may reflect normal statistical errors in the sampling process, he said, but that has nothing to do with manipulation.