No Microsoft browser rival would comment on, much less confirm, that it reported the omission of the browser ballot to European antitrust regulators.
All three of Microsoft's Windows browser competitors -- Google, Mozilla and Opera Software -- declined to comment yesterday on a report by the U.K.'s Financial Times (registration required) that used unnamed sources to say Google and Opera had independently or in combination tipped off the European Commission last summer.
On Wednesday, the Commission hit Microsoft with a $732 million fine for shirking a 2009 agreement that required it to offer Windows users a choice of alternate browsers.
"It goes without saying that settlements can only work if the commitments are scrupulously complied with," said Joaquin Almunia, the head of the EU's antitrust agency, on Wednesday. "They must do what they have committed to or face the consequences."
According to Almunia, neither the Commission nor Microsoft -- which had been left to police itself -- was aware that the browser choice screen was AWOL until a third party reported the oversight.
The Commission has repeatedly declined to name the complainant.
The choice screen, also called the "browser ballot," was not shown to approximately 15.3 million users running Windows 7 Service Pack 1 (SP1) for more than a year, from May 2011 until July 2012, when the complaint was filed.
Some critics have found it hard to believe that neither Microsoft nor the Commission realized the ballot was missing for over a year, and concluded that it was no accident, as Microsoft has claimed.
"You can't say it's accidental for 15 months," argued Robert Lande, a law professor at the University of Baltimore and director of the American Antitrust Institute, in an interview this week. "Microsoft says it was a technical glitch, okay, one month, I understand, you left it out of a batch. But not for 15 months. That doesn't look like an accident to me."
Whether accidental or not, Microsoft did benefit while the ballot screen was truant, according to data from Irish analytics company StatCounter.
For the 15 months from May 2011 until July 2012, inclusive -- the period in which the Commission said there was no ballot displayed in Windows 7 SP1 -- Microsoft's Internet Explorer lost an average 0.5 of a percentage point each month in European usage share.
While IE continued to lose ground during that time, it did so at a slower rate than either before or after: In the 15 months preceding May 2011, IE lost an average 0.64 of a percentage point each month. During the seven months since July 2012, IE lost 0.58 of a percentage point each month.
While the difference in the figures before, during and after may seem small, when represented as percentages they are more substantial: IE's average monthly decline slowed 22% when the ballot was on holiday, then accelerated by 16% after its return.
The missing browser choice screen also coincided with a significant drop in Firefox's European usage share.
In the 15 months when the ballot was absent, Firefox lost an average 0.47 of a percentage point each month, more than double the 0.2 of a point it fell in the 15 months prior, and nearly triple that of the 0.16 of a percentage point in the seven months after the screen was restored.
Mozilla has already made a case that the omitted ballot impacted Firefox downloads in Europe. Last October, after the Commission formally charged Microsoft with violating the 2009 settlement, Mozilla said the missing browser choice screen cost it an estimated 8.8 million downloads.