When Apple said this week that a small number of fifth-generation iPods had shipped with a Windows virus, the company’s statement included the line “as you might imagine, we are upset at Windows for not being more hardy against such viruses, and even more upset with ourselves for not catching it.” Now, Microsoft is hitting back, with current and former employees saying it’s wrong to blame the software giant and that Apple’s quality assurance checks are at fault.

“It’s not a matter of which platform the virus originated [on]. The fact that it’s found on the portable player means that there’s an issue with how the quality checks, specifically the content check, was done,” said Jonathan Poon, Microsoft’s product release virus scanning chief. “Steve, if you need someone to advise on how to improve your quality checks, feel free to contact me,” Poon said, referring to Apple CEO Steve Jobs.

James Abrams, who held Poon’s job for more than a decade at Microsoft, said: “The Apple iPod incident was not about Microsoft having a hardy operating system, it was all about security and process… That Apple would blame Microsoft demonstrates a lack of understanding of remedial security and manufacturing processes. Virus was only a symptom of the problem. Apple didn’t know what they were shipping.”