Before the outbreak of scandal, The Volkswagen Group was notified by individual researchers that the diesel cars were emitting NOx higher than the emission standards, but Volkswagen addressed them as mere technical glitches. When US Environmental Protection Agency (EPA) issued a notice of violation, the company initially refused. Volkswagen only fully acknowledged that they had manipulated the vehicle emission tests after being confronted with evidence regarding the regulators.
On 21 August 2015 at a conference on green transportation in Pacific Grove, California, a anonymous Volkswagen company representative approached Christopher Grundler, director of the EPA Office of Transportation and Air Quality, and surprised him by informally admitting that the company had been deceiving regulators.
Christopher Grundler was determined to get an admission from Volkswagen Group, so he made sure EPA threatened to withhold approval for the company’s 2016 Volkswagen and Audi diesel models.The formal acknowledgement of the regulators was made by Volkswagen executives to EPA and California officials during a conference call on 3 September, 2015. Volkswagen executives discussed written materials provided to the participants demonstrating how Volkswagen’s diesel engine software circumvented US emissions tests.
Soon after the company admitting to using regulator to falsify emissions, Martin Winterkorn , CEO of Volkswagen Group resigned from his post attributed the admitted wrongdoing to mistakes of a few people in the company.
In my opinion, Volkswagen Group should have come clean after it was issued a violation notice from US EPA. The company not only caused a lot of controversy but also panic among public. If the company knew internally that it was involved in wrong practice, it was highly possible that the issue would be eventually come into light. The worst of all, The company was confronted with evidence of using regulators. This proves that company was guilty.